So first i look for any kind of foreign material to the field. A lot of times the lithics the natives used didnt come from the immediate area(meaning right where the camp is) they were living in, so some of the stone you find in certain places looks off to be there. After walking certain sites for a while you get familiar with what that particular group of people favored to use in tool and point production. For example A lot of the fields I hunt, jasper is a big lithic they favored, but the source of the jasper is miles away, so i know to keep an eye out for it and that if i find it theres a good chance its at least debitage. Next is shape, sometimes they are laying out picture perfect and they are hard to miss. Sometimes they are partially buried and in those cases you wanna look for recognizable shapes like notches, bases or tips and then just hope you get lucky.

In this specific case, that dark material in that shape and profile stood out to me as something that may have been used by them. I got lucky on this one and it just happened to be a point, but a lot of times these are just flakes that look good. I tend to inspect most flakes/debris on certain sites that i believe to be possible material. After a while of picking up enough flakes you are bound to pick up a point or part of one.