I'm in the same boat as the others -- for me, muffs hit the stock with rifles and shotguns. I use my muffs only for handguns. For years I used "Sonic" generic ear plugs, but I'm happier since getting custom molded ones 25 years ago. In my corner of the world, they're what we NSSA skeeters use. As my buddy, Big Jim, mentioned: There's often a "plug person" and large shoots. Also, Cabelas
claims to have them available ($18) in their stores. But, I've never seen custom plugs used with a lanyard on a skeet field.
In the 80s is was squadded with NSSA World Skeet Champ Alan Clark in a 12-ga event. It's the custom to arrive at a Skeet field well before your scheduled time, but Al was typically tardy -- one of the championship perks. We delayed our start waiting for him. At the last minute he hurriedly drove up, screeched to a halt, grabbed his trusty R-1100, his vest, a box of shells and headed to station one. Then he stopped and patted his empty breast pockets. Something was amiss! He asked me for a cigarette and took two from my pack, tore the filters off, and lit one. No big deal I'd seen this before -- he'd misplaced his smokes. Then, to my surprise, something I'd not seem before: Since he'd misplaced his ear plugs, too, he stuck the filters in his ears and went on to shoot another 100-straight.