Arousing a guy

Last night I wanted to get my boyfriend hard, but I felt like I wasn't doing it right because it just wasn't working. **Im going to get into detail here** I started by simply sliding my hand down his side, then to his hip, then thigh, before getting to his bulge ( he still had pants and everything on). I rubbed my hand up and down on it using little to no pressure because I didn't know if I was going to hurt him or not, which is also a question of mine of mine. Should I be more rough with it? Anyway, I continued this for a little figuring he would get some-what turned on and hard but it wasn't working. I put my hand down his pants, completely to skin now, and kind of did the same motion but stopped and pulled my hand back out because he was COMPLETELY soft still. I felt like I was going to hurt him if I put my hand around it because he was soft and my hand was sorta rubbing on the skin in a way I would think he would find unpleasant since my hand was in his pants it was "humid" there was that weird skin sticky type feeling that's hard to explain. What should I do at this point? Do I continue to pick it up when it's soft and put my hand around it? I should mention that he was laying down. Can anyone give me some advice please, and be as detailed as possible. It would really help. Thanks.