I've tried many many different mixes over the years, and not really ever found a bad one. Some are more 'stable' than others, and can last indefinitely - with just a little more wetter added, whilst others - eg. grits, shoot their bolt after about 8 hours, and there is basically nothing you can do to 're-temper' them. They are a pretty magical bait though - whether you use them as a pack bait, or as a method.
Grits --- 18oz Instant, 9oz Quick, creamed corn and flavour of choice. Don't get it too wet, and ALWAYS moisten your hands before packing.
Another good choice is pretty much any Calf Manna based mixes - here's one that I frequently use -
1 cup CM
2 cups quick oats
2 cups cracked corn
1 tspn Kosher salt
1 can creamed corn
1 (corn can) water ( lake water - or bottled NOT City water)
Mix dry ingredients well, then add corn and water (if you want to put a flavouring in there - mix it with the can of water)
Mix well (it will be very sticky) put a lid on the bucket and leave for 4 hrs (minimum -- I usually mix the night before fishing) When you open the bucket, it will be set up in a cake. Carefully break it up (not squeezing it too much) by rubbing it between your palms, until you have broken up all the big lumps, and again mix well. It will be pretty dry, but will pack just fine. Keep the lid on the bucket between baitings -- and, if it gets too dry to pack - add a little (very little!!) lake water, and mix until it binds again. A good tip is to have damp hands when packing it, and DON'T overpack, or it will take forever to break in the water.
If you want a faster break with this mix, just add about 1/2 cup of cornmeal.
The last one I'll share is one of the most forgiving mixes I use, and has caught many fish for me.
A 'full' mix - for a long session would be -
8 cups Quick Oats
2 cups Quick Grits
2 cups Wheat Bran
I can Sweetened Condensed Milk
1 can creamed corn
Any flavourings that you like, and a palm full of kosher salt.
If too dry. just add a little more creamed corn.
This is one of the few recipe's that you can successfully halve, or quarter the ingredients - and it still works great.
For short sessions, I'll just make a smaller mix -- and, if I don't use it all, it will keep fine in the refrigerator for a couple of days.
A good tip for making up any 'new' mixes you just dreamed up, is to test it at home - before going fishing, and even then, test it by dropping a ball into the margins where you can see it, on arriving at the water - and note how long the break takes. If you carry some small quantities of the major components in the mix, you can adjust accordingly.
The recipe's I gave are tried and tested - and any substitution of the ingredients will not give the results I've come to know.
There are a plethora of mixes out there - some easy/cheap, and others complicated/expensive. As you get a better feel for what suits any different situation, you can vary the 'flavour of the day' and -- what might not work one day might kill them the next. Just like rigs -- there are many possibilities