Thanks for the suggestion!
Don't act nervous around them. Twirling your hair, fixing your clothes, etc are obvious signs that you're nervous. If they can tell you're nervous around them, it'll be obvious that you like them. Talk to them how you would anyone else.
Don't tell anyone. Telling a couple really close friends is okay but try to keep it between you guys. Also, watch your surroundings when telling someone because if someone overhears you, rumors might start spreading.
If your crush looks at you and you are both looking at each other, don't quickly look away. Doing so will make it look like you are embarrassed they caught you looking or vice versa. If you want to look away, just turn around like you don't mind what just happened.
Be careful what you write. If you write you and your crush's name together or a heart around their name, someone might see and tell someone. And once again, rumors might spread.
Try to become their friend. Be kind but not too kind. Don't say awkward things or they will get the impression that you're nervous. Just say casual things to start conversation like "how was your weekend?" Or "hey! How are you?".
If you see someone flirting with your crush or your crush flirting with someone else, don't act like you care. If they notice you staring at them or if you seem jealous, they'll think you like them.
There ya go! 6 Tips for how to hide if you like someone! :D don't forget to like, comment suggestions, send Monday letters (which I will only be doing if I get enough good letters each week), and follow!