Lip placement, and lip selection.
Forget everything anyone has told you, size of the plug means nothing in relationship to the size of the lip. The size of the lip will affect the action of the plug. A large plug with a small lip and light belly weight will have a tight swimming action for fast near surface retrieves, a small plug with a large lip and heavy belly weight will have a drastic side to side action for deep slow retrieves. By experimenting, you will catch on fast and understand these relationships.
1) Select the lip
2) mark the location
3) Cut the slot
4,5,6) try differant sizes. All these choices will affect the plugs action. Try one, then build another and use a differant lip, and so on.
To test a plugs action, fully rig the sealed unpainted plug, without any weight. bring several differanant sizes of split shot. Tape them in place and test cast/swim.
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