It is very important that you prepare your job properly. If you have neglected this step, the end result will inevitably be disappointing. Always start at the top, and work your way down the wall. We also recommend that you finish with one wall before you start with the next one. This will quickly give you tangible results. It will be more convenient to take a work break when you have finished a wall. Read more how to proceed on our page with hints and advice (link), and on the product package. Good luck!