As I am now entering the "master" division in weightlifting I was reflecting in some changes than lifters should do as they get older. Two things jump at me as being super important to maximize performance in older lifters wanting to improve their performance:
JUMPS! While limit strength can be fairly easy gained at a "normal" rate as you get older (evidenced by a ton of powerlifters hitting lifetime PRs in their 40s, 50s and even 60s), POWER and SPEED are two things that erodes quickly with age. And to me these two physical capacities are immensely important to maximum performance as well a physical appearance. So a lifter should do everything he possibly can to avoid that erosion in power and speed. And the simplest way to do that is to start every workout with some jumping, loaded or not, done for low reps as explosive as possible.
DENSITY. A lot of people talk about how older lifters need to train less often. I personally think that frequency needs to be kept high, but that the duration of the workouts should be reduced BUT density increased. In other words, work at a faster pace while still focusing on performance. Older lifters should spend no more than 45 minutes from the first jump in the workout to the last time the bar is put back on the floor. And in many cases, 30 minutes is better. During that time, strive to keep up a fast pace to get the mechanical work needed for maximum gains. I find this to give better results and cause less aches and pains.
In fact, these two important things should be applied by everybody IMHO!