Bros, here's a good guideline for handling GTP products.
Oil-based stanozolol: cut with 0.25 vol BB, 0.5 vol Oil (e.g. 1cc winny, 0.25cc BB, 0.5cc Oil)
Test Prop:
Get a sterile sealed vial (20mL) and combine the following ingredients.
5mL of 200mg/mL Test Prop
5mL Benzyl Benzoate, USP, Sterile
10mL Sterile USP Oil
You've now got 50mg/mL Prop with >25% BB (assuming GTP uses any BB to begin with, which they may not). PAINLESS - this is a first-hand experience. I couldn't shoot their prop any other way...
With things like their enanthate, I'd suggest using 0.5 vol BB and 0.5 vol Oil to cut it (e.g. 1cc enanthate, 0.5cc BB, 0.5cc oil). You can be very approximate with your cutting agents if you draw everything into the same syringe - you'll still end up injecting the same amount of gear, just in a better dilution.
-M