The Washington State Bartenders Guild

Take any size jar, and fill it half way with dried orange peel
Fill remainder of jar with high-proof vodka (I use Smirnoff Blue Label)
Let sit for one to two months
Strain and filter

To shorten infusion time, shake three times a day and infuse for three to six weeks.

High proof vodka extracts more flavor, so, if possible, use Everclear and infuse for three weeks, then, after filtering, add water to bring down the proof.