Guys - how can you let a guy know you really like them without coming on too strong?

I really like this guy i now work for and he's told me he really likes and i like him too. However, in the past ive ended up being a bit too intense with texting too much, etc and i've ruined it. But i still want him to know i like him a lot. Are there any ways i can subtly do this without coming on too strong because i want to keep him interested.