Usually ppl, after getting sub 1min solves using friedrich method, just keep on practicing and they improve their finger trick! With F2L they just find pair(slowly and rushing with it) and LL they usually spend a bit more time anylysing the situation and which alg to use! That way they get better times! Sub 50sec maybe even sub 40sec! Masteroustly sub 30... not even possible I think.
Then ppl need to learn to look ahead and stop loking pairs! THEY NEED TO KNOW WHICH 2 PIECES THEY NEED TO PAIR NEXT! If u don´t go slow now ur improve gonna be really slow. Never gonna reach sub 20 in 2 months! All u need to do to get out of this thing is that u do slow solves. I mean u need to do solves keeping on the same speed during this whole solve(NO STOP! NOT EVEN ONE!). If u cant do it start again with slower speed to be able to do this! After u have done this u r going to get faster naturally and then it is gonna effect ur normal solves. Finally they are around same speedy and then u have reached sub 25sec possibly! The main step is F2L holding cube on its angle and do all algs using any fingers u need to use. U can spin cube before starting LL it dont take that much time with around 25 avarages. U gonna learn naturally identify OLL and PLL when u do it more and all u need to do is do whole solves concentrating F2L solding the same angle...no cube rotations as long as u can see next pair. That way ur sub 25sec going to be it can reach closely 20sec avarages... The closer 20sec the better! 25-20sec avarage is just avesome time to try build ur cross better way(less moves)!
Then it is time to learn fingertricks. U have learned all cases and steps with no stops and then u need to learn do them fasts! "No delays" so it is time to do it just faster! Then u can just forget those slow solves and concentrate ur speedy solves! U friends should help u to get it fast scrambling another cube when u are solving another

And when u don't have this kinda situation u need to train to do ur LL algs fast! That gonna be till sub 15 avarages...
Then it is just training the whole cube repeating it hundreds of thousand times till u get better and better avarage... ur time gonna stop to around 10 for many weeks but after it u can get better avarages again if u keep on going!
Summarize!
**-40sec -> Do it fastly and try to find ur fingers doing it

I mean try to use ur fingers, not only hands xD
40-25sec -> Look ahead mostly during F2L and do slow solves(No stop solves with slower speed!)! Try to keep the same angle during solves!
25-15sec -> Train ur OLLs and PLLs to sub 2-3sec all!
15-0sec -> JUST KEEP ON TRAINING THE WHOLE CUBE TRAIN, TRAIN, TRAIN....