Picking/determining lip size and Type

[H2o2]

How do you determine the size lip you use for a plug. I have been doing it through trial and error. I thought maybe there was more of an exact method for choosing size of lip. Also id there a specific method for choosing the placement of the lip..ie centered or low on the front of the plug. One more.....does weight of plug or lipsize and placement determine the depth in which the plug will swim? Or is it a combination of all? Thanks, Look forward to hearing from everyone......... Been making my own plugs for the past three yrs. Really great site with some very talented plug makers..... squidhound