World Champion Speaker Ed Tate suggests you break your speech down into parts, practice the parts separately, and then practice remembering the parts separate from the speech order. For example, if you broke your speech into five parts, you could start practicing the speech at part 4, then move to part 2, part 3, part 1, and finish with part 5.
Separating,
Tim Wilson
Professional Speech Coach
Free speaking tips at: http://speakingquicktips.blogspot.com