Well first 4 weeks is too short for a progressive overload approach. You need at least 8-12 weeks for it to really work well.
Then there are several approaches… the double progression method calls for increasing total reps then adding weight.
In the double progression model the goal is to get a certain number of sets one for a prescribed number of reps and weight. When you can get all the sets completed with the selected rep number and the same weight, you can add weight.
For example let’s say that the program calls for 4 sets of 4-6 reps. When you can get 4 sets with 6 reps at the same weight you can add weight.
For example…
Session one you get 6 reps at 200, 6 reps at 200, 5 reps at 200 and 4 reps at 200… so you stay with the same weight
Session two you get, 6 @ 200, @ 200, 6 @ 200 and 5 @ 200… you once again stray with the same weight
Session three you get all four sets at 200 so at the next session you can move up to 205 or 210lbs
That approach is autoregulated because you don’t have a specific plan of when to add weight or reps. t can take you 1 week before you can add weight or as high as 5 weeks.
You can use a planned double progression model too. In that case you would select a rep range (e.g. 4-6) and add one rep per set every week.
For example:
Week 1
4 x 4 @ 200lbs
Week 2
4 x 5 @ 200lbs
Week 3
4 x 6 @ 200lbs
Week 4
4 x 4 @ 205lbs
Week 5
4 x 5 @ 205lbs
Week 6
4 x 6 @ 205llbs
IMPORTANT: You will notice that the progression is VERY gradual, even slow. But that is the key with progressive overload. Most people screw up by going up in weight too much. As the great weightlifter/powerlifter Doug Hepburn said (paraphrasing): “Progress with the smallest implement possible so that you can progress for longer”. Progressive overload is all about gradually making your body work harder. Bigger jumps will limit your capacity to adapt and you will hit the wall way too soon. As long as you are progressing, even if it is 5lbs more, or heck, 2lbs more if you have micro plates, you are fine.
GENERALLY SPEAKING 1 rep is equal to a 2-3% progression, this is especially true when talking about sets of less than 10 reps. So doing 1 more rep with 300lbs is like adding 8-10lbs to the bar, which is why even adding 1 rep per set can become hard.
Another approach that requires you to train a lift twice per week. You use the same weight for both sessions. In the second session you add sets. Then when you get back to the first session of the week you increase the weight.
For example…
Week 1 - Session 1
3 work sets of 5 @ 200lbs
Week 1 - Session 2
5 work sets of 5 @ 200
Week 2 - Session 1
3 work sets of 5 @ 205
Week 2 - Session 2
5 work sets of 5 @ 205
Week 3 - Session 1
3 work sets of 5 @ 210
Week 3 - Session 2
5 work sets of 5 @ 210
Etc.
With this model I like to change the prescribed rep number every 4th week (so doing 3 weeks at the same rep number).
Block 1 (3 weeks) 8 reps per set
Block 2 (3 weeks) 5 reps per set
Block 3 (3 weeks) 3 reps per set
Block 4 (3 weeks( 1 x 5, 1 x 4, 1 x 3, 1 x 2, 1 x 1*
*Note that in that last block both sessions have the same number of sets so you make the second session of the week harder by reducing rest intervals a bit.
I posted a 12 weeks program using that model on my personal page at: https://thibarmy.com/simple-guaranteed-strength-size/