For a crude extraction, mix your bud/leaves with pure acetone instead of alcohol. Put your herb into a sealable container, fill enough acetone to suspend the herb, then shake for 5 minutes. Filter and drain the acetone solvent and save. Mix the herb again with fresh acetone, and repeat these steps two more times (shake/filter). Allow the collected acetone to evaporate completely, and you'll have a crude thc oil extract (still contains non-cannabinoid essential plant oils and stuff). You can then mix the oil with alcohol to drink, fatty food to eat, or mix with some sort of non-toxic, non-polar solvent for a topical spray.