1. Repetition

Professional actors are said to learn lines most effectively by rereading a play or parts in a play many times over a short period. As an example, they may read something to be remembered 5 to 10 times a day over 4 days.

2. Keyword/Journey System

An alternative approach using mnemonics is to use the journey system, with a stop for each line.

At each stop you can either code the key images or words, or can adopt a technique where you associate each word in the line.