I used sustanon 250 when I started TRT. 0,35ml E5D was a good protocol for me. I tried 0,5ml (125mg) E6D, but that was too much for me.
The smaller dose worked well and I was doing pretty good with that protocol. I strongly recommend that your test your peak and through values when you evaluate the efficacy of your protocol. At some point I also added 0,25md of adex on the injection day.
I used to store this form of testosterone in a syringe in my fridge. This worked well and it did not lose any potency.