Insert or straight?
As a general rule, an insert tip is used for stillwaters and a straight tip on rivers. Inserts are more sensitive, and in normal conditions they are perfect for stillwaters as you’ll see every bite. Use one on a river, however, and it will be far too sensitive, dragging under with false bites. A thicker ‘straight’ tip, however, enables you to fish with the line tripping bottom, without it pulling the float under.