I've had more success with westside type programming than any other. I think it's because it really allows me to push hard without getting the overuse injuries of programs that have me going hard on the comp lifts week in and week out.
Just some main points.
*Westside DE box squats can work, but you have to use very good form. They help me pop right out of the hole on a free squat.
*I do best to include the comp lifts. For squat, I pick something from Prilepin's table after DE work and same with bench. For DL, I just do few speed pulls or double paused deads after DE squat and comp squats. The idea with the comp lifts for me is just to get some practice in without hurting recovery too much. That's what all the other work is for.
*I get the most out of it if I block it up some. Like 3 weeks with a 5RM for max work; higher reps and density for supps, higher volume no accomodating resistance for DE work. 3 weeks 3RM, higher intensity and less volume for supps. Some accomodating resistance for DE work with lower volume. Last 3 weeks 1RM for ME work, even lower rep for supps but don't go below what would be a 6RM in that movement. DE work uses even more accommodating resistance and less volume. Also, I do less assistance work as intensity rises simply because I can't recover from it at that point.
*This programming is huge on developing work capacity. At some point, you should be able to do so much work that the main workouts become inordinately long and then you take some of that work and do feeder workouts on other days. These should help your joints stay healthy and/or work on weaknesses and be very general in nature. As in, don't do your comp squat this day, maybe do some goblet squats and back raises and abs or whatever helps you with your specific weakness.
*It takes time to figure out the best exercises for your weaknesses. Sometimes there really isn't a specific weakness and you can just pick stuff real close to the main lift. I don't really get much out of GM's anymore, but there was a time that whenever I was able to increase my volume on these my DL and squat would go up. But after a while they did nothing for me. So that is to say, exercises that might have helped at one time may not always be helpful.
*For the ME work, don't go so heavy and hard that your form puts you at risk. But it doesn't have to be totally perfect. The weight should be kind of scary, but you should only rarely fail a weight. I find I do best if I don't psych up for the lift. I get a little nervous energy at times but I'm not going out of my way to psych up.
Also, the ME work should help you strain through the angle, movement, and muscle pattern that's weak with on your comp lift. Like if you suck at staying tight at the bottom of a bench press then paused bench presses might be a good movement since it really emphasizes staying tight there.
*Personally, I have to free squat both lower body sessions to keep the squat groove. But only one of those days is the comp squat.
*If your feeling beat up, it's okay to pass on ME work and do some more DE work or GPP work like tire flipping or sled work. I've read they actually do that at westside and I find it can be helpful for me.