I'm unclear exactly what detail you're seeking, so I'll lay out my full routine from beginning to end. My 10mg vials stay in the freezer until I need one. I let a vial sit out roughly ten minutes to reach room temperature before mixing. I add 2ml of bacteriostatic water to dissolve the contents, then move everything into a cartridge designed for an injection pen. Once the cartridge is loaded, I clear any trapped air by sacrificing a needle and cycling through doses until nothing but liquid remains. Videos online probably demonstrate the steps if that part interests you.
My weekly amount is 1 mg, which a calculator converts to 20 units on the dial. Injection day means attaching a needle, turning the dial to that setting, inserting into a soft spot, pressing to deliver, then safely discarding the used needle. The pen itself rests inside a pencil case in the fridge between uses, and I ignore any temperature guidelines.
Two parts of this approach do carry obvious downsides. I skip filtering entirely, which raises the risk I'm accepting. I also keep and reuse mixed vials well past the 28-day window. Filtering might enter the picture someday, yet I haven't researched the steps or gathered the needed items. I'll stick with longer cartridge use for now. My personal sense is that they hold up longer than the stated limit, though this rests on nothing beyond my own guess. Should problems appear later, responsibility falls only on me.