Unless your body is morgue-ready – in which case, please remain in situ – then your living, breathing human self is beach-ready just the way it is. If you have a pulse, you already have a bikini body. Or indeed a mankini body. We all know this in theory. Yet these sensible thoughts are easily spouted but not so easily, um, embodied. Many of us find it relatively straightforward to be kind (and relatively less judgmental) towards other people. Because all you have to do is remember not to be a cruel git. But when it comes to our view of ourselves, we can be over harsh and critical, submitting ourselves to a level of scrutiny that we wouldn’t dream of applying to others. But the 1980s idea that we must all prepare ourselves for the Great Unveiling of the Socially Acceptable Flesh and improve our aesthetic qualities before we venture near a beach or swimming pool … Well, that has kind of had its day. How often do we have the chance to get the sun on the bits of us that rarely make contact with the outside world? Why would you squander that chance? Here’s how to feel confident with your body this summer and all year round. 1. Remind yourself how pointless fad diets are The concept of the “beach body” is predicated on the ill-advised idea that you must suddenly embark on a short-term seasonally motivated plan of action that is alien to you. “We need to get away from the boom or bust mentality that often comes with weight loss,” says nutritionist Emma Bardwell. “I see a lot of women embarking on faddy, restrictive diets and extended fasts, declaring they will ‘cut out sugar completely’ and ‘only eat after midday’. This is difficult and unsustainable.” 2. Dress and shop for your body the way it is today The body you see in the mirror on this very day will never be quite the same again. Chloé Dall’Olio, video director at the beauty company Trinny London and the host of the online series The Body Talks, says: “It’s all about highlighting the person who you are today. Yes, be inspired by other people. But it’s about what assets you have and celebrating them. The bigger and the smaller bits. The bits that have been shamed and the bits that have been praised.” Long live all our bits. 3. Rest is the cornerstone of confidence Heed the motto of the yoga teacher Paula Hines, author of Rest + Calm: Gentle Yoga and Mindful Practices to Nurture and Restore Yourself: “Imagine how different the world would be if we were all well rested.” She says: “You can’t be confident if you’re tired and wired or burnt out. It might not be about taking a nap, but finding something that works for you – and is good for your nervous system – is essential. I saw a video recently on social media of a young boy asking his wailing little brother if he’d had a nap. He hadn’t. So his response to his younger sibling was: ‘Well, you need one!’ It was funny and relatable but I do think this applies to grownups too. Rest gives you perspective and clarity.” 4. Do not dress apologetically It’s a cliche, but wearing “loud” clothes – or anything that doesn’t feel like “hiding” – lifts your mood. Nickie Reynolds, the owner of Gold Dust Vintage, explains: “Dress in colours that make you feel good about yourself. This will instantly boost your confidence. If you’re not sure what these are, just start with the colours you love. And experiment. You can begin with introducing ‘pops’ of colour.” Ignore clothes sizes, especially if you’re shopping vintage. “Get to know your measurements and the styles and cuts of clothes that you enjoy wearing.” 5. Link your body confidence to sustainable fashion One of the main reasons we buy too much is when we shop from a place of insecurity. Hands up anyone who has ever shopped for a body they wish they had or a body they used to have? (All my hands are up. Or they would be if only I could lift them in the air while wearing this teeny tiny blouse.) In 2014, a UK survey by a lingerie company found that 48% of women have bought clothes that are too small for them. We can only hope this has improved over the past decade but it seems unlikely. Ask: “Does this fit me right here, right now? Do I want to wear it right here, right now?” If not, maybe let the shop or the website store the item “for safekeeping” until the craving passes. Buy fewer things and let them fit better. 6. Park your insecurity when it comes to fitness Exercising – especially in class, or anywhere in public – can seem daunting. This is a chicken and egg thing. By which I mean that when you are lacking in confidence in your body, you are less likely to exercise. And the less you move, the less confidence you have in your body. Hines says: “If you’re attending a class for the first time and you’re feeling nervous or insecure, then I’d suggest having a word with the teacher beforehand. I’m so used to people letting me know that they’re new or it’s their first yoga class and they’re feeling a bit anxious.” Admitting your vulnerability makes it less of a big deal. 7. If you do want changes, make them small and easy If change of some kind really is your goal, aim for small, consistent habits that you can maintain. Seek out sensible health advice that resonates with you as an individual. We are not all the same. We do not all want to look the same. And we are not all motivated by the same aims. That is OK. And if change is not your goal, that is also OK. 8. Dress for your character not your physical shape Marleen Beevers is a fashion psychologist and the author of the forthcoming Satisfashion, a book about using your attitude towards style to cement the idea that you are “enough”. Our style should be about expressing what we think of ourselves, she says. “Who are you? And what do you want in life? Focus on your personality strengths. Challenge your negative thoughts with positive affirmations. Limit your exposures to negative triggers and social media campaigns.” 9. Buy amazing exercise clothes This is a corrective to the previous advice about sustainable fashion. If an outfit will make you move your body, then buy it with reckless abandon. Take a look at the meticulously coordinated gym wardrobe of musical theatre goddess Marisha Wallace (currently appearing as Miss Adelaide in Guys and Dolls) who mostly wears Sofina Active. Hines recommends jumpsuits from Thought, and stretchy jersey trousers and vests from Asquith and Sweaty Betty: “I don’t do leggings or formal yogawear. Some of my most faithful long-wearing items have come from M&S. Sometimes just wearing something comfortable can make you feel relaxed.” 10. It’s OK not to be “body positive” all the time No one loves themselves constantly. So it’s OK to feel unconfident occasionally. Just not all the time. Hines says: “We all have negative body days. I’m not sure I believe anyone who says they never do. But one thing I suggest is to focus on what your body does for you – whether it’s getting you through the day or achieving a personal best at the gym.” One of the greatest moments of my own life was having a “personal best” in a 1.5km swim because I beat my own record by 50 seconds. (Count. Them.) This achievement mattered more to me than the fact that I had taken well over an hour to cover this distance, whereas the fastest swimmer could cover it in under 20 minutes. We all need our own PBs. Hines sums it up: “When I started focusing on what my body could do, it shifted my mindset over to a place of gratitude, away from constant negative self-talk. Our bodies really are miraculous, and you only get one, so you may as well enjoy it.” Happy High Status: How to Be Effortlessly Confident by Viv Groskop is out on 29 June (Torva, £16.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply.