[Help]Icons!???

[BayBay]

Hi guys!, my question is:

 

what is the best tool to add icons ? i been using model viewer, i open the wep then i export it as a png, i open with paint, cut the wep in a small little square but it looks a bit blury and not really good. Is there something i can do so the icon im cutting and pasting looks better? not to blury. I dont know if you guys are understanding what im saying...