What should I work on between reining lessons?

Between reining lessons, practice should be focused on the specific corrections and skills identified in the most recent lesson rather than on general riding or full pattern runs that may or may not engage the elements being developed. The trainer's feedback from a lesson identifies the specific gaps — a position element, a timing issue in a particular maneuver, a rate control problem — that are currently limiting the rider's development, and the practice sessions between lessons are the opportunity to work on those specific things before the next lesson assesses progress and adds new material. Write down the corrections from each lesson immediately afterward while they are clear, and use that list as the agenda for each practice session rather than riding without a specific objective. If the lesson identified that the inside leg is not maintaining forward energy through circles, every circle in practice should include specific attention to that leg. If the lesson identified that the seat cue for the stop is arriving too late, practice transitions from lope to walk specifically focusing on the timing of the seat cue before the rein is applied. Beyond the specific lesson corrections, between-lesson practice should include the exercises that build the foundational physical attributes that all reining riding requires: transitions to develop rate control, lateral exercises to develop body control and leg independence, and general loping work to build the position stability that makes precise aids possible. Avoid drilling full patterns between lessons as the primary practice activity, because pattern drilling without specific technical focus tends to train anticipation and confirm existing habits rather than develop new ones.