I have just been reading through this post and I was in exactly the same situation as you 3 years ago. I did a day course for acrylics which was no way enough training, needless to say I went away with hardly any knowledge, I used ASP products and quite literally my clients nails were 'rubbish'. I stopped as it knocked my confidence but last year I re trained with NSI and absolutely love their products. I am alot more confident now as I know I have been trained the correct way and most of my clients nails last a good 2/3 weeks however I always get the odd client whose nails lift or don't last and it does knock your confidence but I know I am doing the correct procedure and it is more likely to be the clients nails opposed to the way I do them for example a client called back today with lifting after only having the acrylic enhancements on Monday but her nails were very badly bitten (little more than stumps) and she bites the skin surrounding them constantly therefore I know that the way her nails are means the enhancements are not going to last her as long. It is also about 'practice' just keep practicing and eventually you will be perfect. My trainer with NSI told me it would take a good 4/5 years until you would be perfect as being a nail technician really is a skill that takes time to perfect!
(sorry about my long essay lol) xx
(sorry about my long essay lol) xx