Discipline yourself to practicing very slowly. For the first few days, practice slowly only. I've applied this technique to Mephisto Waltz, for recent example, and find that at least half of it is memorized though it has been only six days. Everyone in my studio uses this technique, and some have made greater progress than others (one student learned and memorized Carl Vine's Sonata in one week, another Rachmaninoff's Rhapsody on a Theme by Paganini in the same amount of time). The idea is that with much repetition at a slow tempo, the fingers know it and the mind can learn notes from the fingers and music from the score.