Been a long time since I've seen the "How to..." for ear plugs.
I used to be a Junior rifle coach so each new class I had to show / tell the kids how to protect their hearing. So, for grins and giggles, I'll review here for maybe newbies.
Roll the foam plug into a long stick. For your right ear, reach over or behind your head with your left arm, grab the top back of your right ear and pull up and back. This straightens the ear canal for easier plug insertion.
Insert the rolled up plug, and hold it momentarily with a finger of your right hand; you will feel the plug begin to expand. Hold it in place until fully expanded.
Reverse and repeat for your left ear.
Depending on who is shooting what around you, this is usually enough for small bore, but for larger rifles and handguns, I would recommend over-the-head headset, especially with the proliferation of short barrel 223's.
Now, there may follow a discussion of everyone's favorite ear protection...but the above is the minimum acceptable.