It will get better with experience. Quality of glue lines depends on which tools you use and your skill with them, glue surface prep, clamping pressure, etc. Without knowing/seeing those things, it's kind of hard to advise changes.
For gluing handle pieces onto blanks, I like to shape them so they're mated perfectly, then prep with a toothing plane blade, then glue up with epoxy, clamping firmly. With the grooves from the toothing plane blade on both gluing surfaces, it's virtually impossible to overclamp and starve the joint of glue.. Glue lines are almost always invisible.