Just lay out consistently, at least a few times a week. I get the best tan after going somewhere with water, sand, or cement, because of the reflection. Try going to the beach, water park, lake, river, lay in a raft in a pool etc. Use some tanning oil. If you have fair skin then i wouldn't go with out sunscreen, because you'll burn(obviously) I rarely where sunscreen, because i don't have to worry about burning, and i get tanner with out it. Personally I hate spray tans. I hate the way they look. I never go in a tanning bed either.
It take time, but you'll be satisfied with the result (: