This might be a good place to collect all my favorite "extend the LP" tricks into one place. Note that this is not an exhaustive list. For example, I am leaving out things like switching from 3x5 to 5x3 for upper body lifts, and doing 1 on / 2 off, because they necessitate significant changes to the workout schedule (significantly longer workouts, non-repeating weekly schedule). I'm including the things I use often, that do not necessitate any significant changes to the basic schedule and set-up of the rest of the LP and that most people can do without a problem.
SQUAT
1. Trick: Make the middle day a lighter day with 2x5 at 70-80% instead of adding 5 more lbs and doing 3x5.
When to add: With a coach - when failure is imminent. Without a coach - after you have failed, when ramping back up after your first re-set.
Extension of LP: Very good. I have found this can be run for a fairly long time.
2. Trick: When you add weight on your two heavy days per week, only add weight to one of the three sets. The remaining two sets should be done with 90-95% of the weight of the new top set.
When to add: When you think you're not going to be able to keep adding to all three sets for more than one more workout.
Note: Some people do better with the top set first, after a warm-up. Others do better with one of the lighter sets first, and the top set second, then a final back off set. By this point in your LP, you should know if you do better on your first or second set.
Extension of LP: Small but useful. You're not going to get months out of this. A few workouts to a few weeks, probably. But that can mean 15-30 more lbs on your set of 5, which is something a later Intermediate lifter would kill to be able to do in 2-3 weeks. So use it.
3. Trick: Same as #2, except use a top triple, and two back-off sets of 5.
When to add: when you fail the top set of five, just make it a triple going forward. Continue doing 2x5 back-off at 90-95% of that triple.
Extension of LP: Small. Probably not even worth doing most of the time, but if you really just don't want to let go of your LP, at least do it this way so you don't detrain on all your volume leading into Intermediate training.
Press and Bench
1. Trick: Microloading. Add 1-2 lbs in the press and 2-3 in the bench press, instead of 5 lbs.
When to add: Depending how well you started at the right weight, after about 2-3 weeks. As a coach with a developed eye, I like to do this one workout before I see that 5 lb jumps will no longer be possible.
Note: I have coached hundreds of people using microloading with well-calibrated weights, and it works very well. I personally have used it, and have coached dozens who have also done so, using cast iron plates at globo gyms where the deviation of the plates (lack of accuracy) might negate the precision of the microloading. But it still works! Maybe it was a placebo effect, maybe it works because while, in any given workout, the weight wasn't as precisely titrated as it was supposed to be, on average it still was. I don't know. But it still works.
Extension of LP: Good. Can get a lot more workouts with added weight this way.
2. Trick: Same as #2 in the squat above
Extension of LP: Small but still significant enough to be useful.
3. Trick: Switch to one set of 5 at 90-95% and then 3x3 at a new microloaded heavier weight.
When to add: When you can no longer complete sets of 5 at a new heavier weight.
Note: Pressing and benching generally requires less rest than squat, so I've found doing 4 sets (with one being lighter and easier) is feasible for most people, more so than extending the work
to 5 sets with all being heavy.
Extension of LP: Small but still significant enough to be useful, if you have time to add the set.
DL
1. Trick: Switch from a set of 5 to two triples.
When to add: After you've re-set, when based on your previous experience, you're about to fail again.
Extension of LP: Small but useful.
2. By this point in the LP you should have reduced pulling volume to once a week (or maybe less, if you're doing the DL/chin/clean/chin schedule). Now, bring it back to twice a week, with one being a top triple and the other day being 1-2 sets of 5 at 80-85% of that triple.
Note: If you still want to clean, just do your cleans as warm-up for the light day DL. You'll need to reduce the clean volume, obviously, but you can still do some.
i.e. You were cleaning 185x3x5, and pulling 335x3x2. Now you'll do 340x3 on your heavy day, and 275x5(x2) on your lighter day. So for your lighter day, you can clean: 95x3, 135x3, 165x3, 185x3, 195x2, 205x1-2, and then go to the DL or do one more DL warm-up single in between (245x1).
Extension of LP: Small but useful.
*Note that my "extension of LP" sections are what I've found in general, not necessarily capturing the experience of every person. For example, I have recently coached someone through an LP who failed 295x5 brutally, and who I switched to a top triple + two back-off sets of 5 at 90-95%. I list this trick as small and probably not even worth doing. That's usually what I've found. But this guy actually ran it up to 350x3 and 320x5x2. So these are general notes. Exceptions, as always, may apply.