Personally I switch it up 2 weeks each than move to the next.. In this order: Jack3d is great (no crash for me unless I do 2 scoops), oxyelite pro (1-2 capsules), ECA than clen/t3.
Bare in mind though I'm talking about my wake up pre cardio. I'm on an ongoing cutting LBM workout regime. I should have run a log but it's too hard for me to be accurate with weight / bf (I'm a paraplegic so kind of difficult as you can imagine).
I just came off a tren/TnE cycle and am mid way through my PCT. Using ipamorelin, CJC1295, igf, HCG & bridge to keep my gains... Lost 5 belt sizes and almost have my 6 pack back.
Stims are great but if you stay on too long / don't switch up you will definitely crash.. Just my 2cc's
E