If you have a boyfriend, the overwhelming odds are that he's attracted to you. If he were not, then he would not be your boyfriend. However, after people have been dating for awhile, they occasionally start to take one another for granted. While he is probably still attracted to you, he may not show it like he used to when you first started dating. So, getting your boyfriend attracted to you is less a matter of appearing attractive and more a matter of encouraging him to express the attraction he already feels.
Avoid talking about your weight and appearance all the time. You may feel that talking about these things is a good way to make him attracted to you, but you are incorrect. He would not date you if he found you physically repulsive; by being less obsessive, you are showing that you are secure and confident in the relationship, which will make him more attracted to you.
Join a club, society, sports team or any other organization that does not involve your boyfriend. While you and your boyfriend will share many things, you don't have to share everything, and this includes interests. By nurturing your independence, you will appear more attractive to your boyfriend.
Let your boyfriend have his independence. Just as you should have your independence, so too should he have his independence. If he feels like he can do his own thing from time to time, he will value the time he spends with you more highly because he will have something to compare it to.
Be honest with your boyfriend. Honesty is refreshing, especially from the people we love. So if there's something you want him to change about himself, such as the fact that he does not clean up after himself, tell him. Don't bottle it up, as he will sense your unhappiness and become less attracted to you.
Show confidence in yourself by supporting your own successes. If you do something well, and your boyfriend congratulates you, don't downplay it or shrug it off. Rather, you should claim responsibility and accept that you are a capable person. The fact that you are this confident and have the ability to back it up will make him more attracted to you.