In all honesty, I have never been a person who has really been bothered by my appearance on a daily basis. Yes obviously I somewhat care, but what I am trying to say is that it isn't something usually on my mind. However, occasionally, I do have moments where it does come to mind and I just don't feel beautiful (and that tends to translate to how I feel internally). How you can feel about yourself on the outside can affect your general mood. 

What to do when you're not feeling so beautiful

Assess what is not making you feel yourself.

I find most of the time when I don't feel beautiful there is a reason behind it. It usually is that I am focussing on an insecurity of some sort - whether that be how my body looks or generally my personality. When I realise I am in this state I find remembering that everyone has things they feel insecure about and that most of the time I just can't see other people's insecurities helps. I am not the only one feeling like this. I think it is also worth noting that what you look out for in others and think they are better at or looks-wise have it "nicer" is often a reflection of your own insecurity - 9/10 most people are too busy focusing on their own insecurities to notice yours. Even the 'flaws' you may notice on others are often guided by what you actually feel insecure about. What to you may feel like a big deal is probably something which a stranger or even your close friend would not even notice. We overanalyse ourselves so much more than other people do. 

In the midst of everyday life, it is surprisingly easy to stop doing things you enjoy. Before you realise it, you don't feel beautiful, and find yourself in a slump. Reflect on your current situation and your surroundings - think about the impact they are having on your day to day life and whether you have stopped doing a lot of what you enjoy. Then try and make the time to do something that excites you. Sometimes, what makes you feel less pretty both on the inside and outside is having spent a while not doing what you really enjoy in downtime. Doing what you love gives you time to disconnect and can give you a feeling of purpose which translates into feeling good about yourself.  Often when we stop doing what we love is when we lose our sense of purpose and start slacking on self-care and outer appearances, which in turn makes us feel worse. It may not be immediately obvious that you aren't doing a lot of what you love as you may be going through a phase with a lot of stress and work- I know I have been there. That is why I think it is so important to focus on why you feel less beautiful and make a conscious effort to be aware of your surroundings and the current situation you are in.

Wearing something you feel amazing in can have a surprisingly huge impact on how you feel and your general confidence. It is not about what your friends think suit you, but what you want to wear and what makes you feel beautiful. I have also found making time for self care tasks like shaving (if it is something you like doing) can also help me feel myself and more beautiful in my own body. Or if you like wearing make-up, go ahead and do that. But, make sure that whatever you are doing, you are doing it for yourself and the way that it makes you feel. Any time you invest in your appearance should be because you want to and it is your choice and never because you feel pressured to do so. 

Think about what you love about yourself - it may sound cliché, but by focusing on what you do like about yourself, you are not concentrating on what you don't like as much and what makes you feel less pretty (both on the inside and out). If you are not in a headspace to think about what you do love about yourself, think about what strengths others have pointed out about you and remember them.  Or alternatively, observe what you do have without judging yourself. Just be aware it is present, and another part of you without deciding whether it is good or bad. 

Don't compare. 

I know we all compare to a certain extent and that it is inevitable to not compare at all. Society has taught us to compare ourselves to others as a way of judging our worth. However, what is not often spoken about is that most of the time, you will be comparing your low to someone else's high. We don't see everyone else's low points and it is easy to fall into the trap of thinking that others lead perfect lives. Be your own kind of beautiful - we are all on our individual journeys and will be doing things at different paces. Being unique is beautiful and there is something special about it. You don't need to look like a 'model' and what the internet and society perceive as beautiful. Nor do you need to be into the same things society regards as valuable and desirable - have your own opinion and own it.  Be respectful of others, but know that having a different perspective allows for diversity and growth. If everyone had the same views on everything society would never move forward.

Helpful links - https://www.wikihow.com/Feel-Beautiful 
https://wanderlust.com/journal/look-inner-beauty-find-outer-glow/
https://www.buzzfeed.com/hnigatu/things-to-do-when-youre-feeling-down?utm_term=.pn9MBM75W#.qdJglg7Jq