Finding someone who is attractive and thinks you are wonderful is great as long as you know where to put a full stop! It is easy to get involved in a horny and passionate casual relationship but the things start getting complicated if you get attached.
Ouch! Deeper feelings and real desperation for love is not good for a casual/fwb relationship and no matter how much you avoid it, there are high chances to delve deep into it! It's innocence of human nature! Hence it is required to take some precautionary steps so that your little innocent heart is not hurt in the long run and you continue to reap fruits of your casual relation!

Pursue your life outside of this relationship
The initial attraction and sharing matters and things might increase your time allocation towards this casual relationship. But you need not let these thoughts dominate your mind and allow yourself to aggressively pursue your life outside of it. Meet your friends; spend time with your family, sneak out time for your hobbies, career and social life too! Just stick to your routine and don't waste your time in adjusting your routine and habits according to him.
Communicate before you enter into this relationship
The vehicle of Friends with Benefits relationship has two wheels and thus it is necessary that before entering into this casual mode, you communicate and set the right expectations. If any of you start developing feelings towards each other then it would be hurtful to both of you and will kill the fun and excitement of casual relationship. Hence it is necessary to set some rules and adhere to them as you proceed further on this track.
Keep reminding yourself the good things
No strings attached, no commitments to fulfill and no responsibilities to handle, yet enjoying the life completely with abundance of sex and an option to change anytime! This is the mantra of avoiding getting attached in casual relationship. Just keep yourself reminding the fun and excitement you are drawing out of this relationship and how the flowers will fade in case you wanted to convert it into a real relationship. Things will become boring and stale as sense of age and responsibilities will start pitching in!
Don't stalk
This is a very common habit that all of us have! Stalking him/her by visiting social media profiles is not something which suits you! He is not your ex so don't try to mix yourself up in his life. Don't overthink as to why he is not texting you whole day as you have nothing to do with it. You both are in casual relationship and it is necessary that you respect your relation. Don't assume that his every post or tweet is dedicated or pointed towards you. If you want to maintain the boundary as desired in casual one, then don't punish yourself by stalking him online.
Don't buy gifts unnecessarily
Exchanging gifts actually helps in tying the knots of hearts. Thinking about a suitable gift and then extracting time to go and buy it is too much effort for a casual relationship. If you are doing it then it means you are going an extra mile which is actually not required. Here is a better option! Treat yourself and shop for everything which you want to buy for your good-self. You would just feel awesome!
Say No-No to cute nicknames
It is very easy to start using words like honey, darling, babe etc. They are indeed cute but are not certainly meant for your casual fwb partner. So call out each other by name and converse like you do normally with other acquaintances and colleagues and peers. Keep your inventory of cute nicknames and pillow talks for your partner in serious relationship. You are just in mood of lying down casually and hence keep yourself away from all these. The more you will call him/her cutely, the more you would feel attracted towards him/her. So keep your conversations casual.
Don't let him/her being the only man/woman in your life
It is necessary for both men and women to have friend circle consisting of both males and females. This is so that when you engage in a casual relationship, the genuine sex attraction should not let you get attracted towards him/her. This also means that you are open to options and continue seeing other people. So don't give your casual partner so much importance as if he is the only man in your life.