I am a speedcuber. I average about 8-9 seconds on 2x2, 35-40 seconds on 3x3 and about 3 minutes on 4x4. I need some tips.

On 3x3, I am pretty fast except for F2L. I use intuitive by the way.

On 4x4, I need a lot of improving. I get about 40 seconds for centers, 1:20 or longer for edges, and about 1 minute for 3x3. Parity is a little longer. For edges I do 4 pair. I do 2, slice, 2 more, then slice back.

On 2x2, I am pretty happy. I do Ortega. I might learn either Guimond or CLL.

Thanks for your help.

Maybe you should be asking this question on the speedsolving forums?

I would just search on the speedsolving forum instead of actually asking. If you ask them they'll just give you a link to a bunch of threads asking the same question.

In answer to your question, if you want to get faster, you must practice. And learn full PLL if you really want to. And practice. You could also try practicing.