Some heads up help

[Cactus Cactus]

I play very well at limit poker. Especially short handed and heads up. Finally I started to study no limit poker. I started at full tables and learned the basics and within about 3 days I was so bored. I'm used to the short handed/heads up action. So I started playing heads up no limit and I am doing quite well, but I have some questions

The say generally you want to raise 3-4 times the BB in full ring. But if you are HU, SB on the button. blinds are 2-4, I feel that if you raise 3-4 times the BB your opponent folds too much and you only get called by a better hand. When I first started playing I was raising 14, but then I realized that this was too much, so now I am raising like 10.

What should I be raising?