All you need is a solvent strong enough to keep it in solution. I personally use 151, but others use everclear and/or PEG.
The recipe I use is 65ml of everclear to every 1gram of var powder, which results in approximtely a 15mg/ml solution. I've tried to go as high as 20mg/ml, but it kept falling out. In fact, the 15mg/ml falls out for the first few days, requiring that I reheat/shake until it's all solution, no precipitate, again. After a few days of this, it tends to remain in solution. I measure with an eyedropper. Get my bottles from specialtybottles.com and etch a 1ml crosshatch on the glass tube to measure. Using powder is SOOO much cheaper than commercial tabs and caps that I'll never go back.
It sounds much more complicated than it really it. The only hard part is scoring a reliable source.