Just buy them.from your local hardware . I dont buy their cheapest brand but just ones a step above and they work just fine . Nothing wrong with learning to sharpen drill bit but you can't do that with the small stuff , get a sharpener for the little ones if you like , I did for a while but not necessary ... Just buy another bit . They last a good longtime . When drilling dont bear down too strongly , many do and break bits and dull them quickly . Feel them cut and back off to clean often ... Most are small size and I made a holder for my usual bits , I use those sizes constantly each day , and I have a pile there also ....sometimes you need a bit you dont usually use so that pile comes in handy sometimes .. .