well, all the linear program does is repeat the movements and increase resistance. That is the only way it attempts to progressively overload your muscles. As you get stronger and more advanced that will show diminishing effectiveness.
Increasing sets, repetition, ROM, frequency, time under tension, intensity, decreasing rest time and changing exercise selection are all means to the same end. If you demand the same thing of of your body it isn't going to respond differently. Even bodybuilders use this principle by going for extra reps, drop sets, changing exercises to make them harder and alternating the isolation exercises they use, etc. But in strength training it is even more crucial.
Maybe you should go to EliteFTS and read about westside. I'm not saying you should do that program, but it gives you a good idea of how a well set up progressive overload program will work. The lifts carry over to each other, you alternate the max effort lifts when you stop showing progress, and you frequently change repetition amounts and other factors to overload your system and constantly hit PRs, and eventually deload and then repeat. Everything is in cycles.
Sheiko
http://www.elitefts.com/sheiko/
for westside just read up on elitefts, search it on tnation, search westside and westside basics on google etc, there's stuff everywhere
There are numerous other progressive overload cycles for PL online everywhere. You can DEFINITELY make a program on your own and figure it out for yourself, but you should probably take a look at how some of the more popular programs are structured and figure it out. Plenty of people don't even need a program and can just go in and switch up what they are doing + do assistance lifts and show great progress continuously, but I think it's pretty tough and reading up on westside would definitely help you figure it out. I personally don't have a great feel of that stuff and usually end up making mistakes when I leave it to myself to figure out my program and switch up exercise selection and everything