I went to an Efile / Speed Training class a few years back.
The educator who held the class books her clients back to back every hour!
She taught us a really good method to try and build up our times. She splits her service into 3 x 20mins - 20 mins for prep, 20 mins for acrylic application, 20 mins for final filing and painting.
If she takes an extra 5 mins with her prep then she knows she will need to shave 5 mins of the rest of her service.
Now believe me I am not saying this will be possible straight off the bat, I still am nowhere near this speed myself. But its a great way to work out where you are spending the most time and then trying to improve your timings, even if its only 5 mins. So start timing your service to see where it is you are spending the most time and then try to work out ways to reduce the time.
I spend a lot of time prepping and have since been able to identify this and try to improve on what I do, time wise. In saying that however I find my application is really quick as I have spent time mastering my ratio and therefore my application is good and my end filing does not take long at all.
But if you are just starting out dont get too hung up on your time. Its much better if you do correct application and then the speed will come.
It will seem like it takes forever but you will eventually get there, even if it takes a few years. Dont give up and practice practice practice.
Good luck x