WET'S BASE MIX
I learned this by rote and sweat labor over 45 years ago in 1972. There were no written recipes and 20 years before the word internet was even heard. Everything is geared to mixing in a standard (6cf), wheelbarrow. Altered slightly over the years, but nothing drastic and I will note the old and new.
VERY similar to LC's #1 mix and he probably learned it like I did, from a old timer who was kind enough to pass on the information for the price of the shovel work making a few batches of mix.
I use 5gal buckets for rough measurements so the wheelbarrow isn't overfilled, but the final measurements are always eyeballed till it looks and feels right.
BTW, 5 gallons in a 5gal bucket is a few inches from the top, so filling it to the top edge is a bit more than 5 1/2 gallons.
Peat moss: After 'expanding' by either screening or just rubbing it between your hands to remove any clumps or still compressed moss, I'll fill 1 1/2 buckets, ~7.5 gallons or 1cf. A bit more or less is fine, don't stress exact measurements.
Perlite: Full to the top 5gal bucket. After eyeballing at the end there is usually ~6 gallons of perlite.
Pine Bark fines: ~3 gallons or a bit less. Back when, you could get actual bags labeled Pine Bark Fines as a graded size and no extra cost. I've never seen them since moving to SC. The closest thing is pine bark mulch and I run this through a 1/2" screen to get what I like. They should be flakes, fingernail size or smaller. No big chunks or long stringy stuff. Back when, the mix called for 3 shovelfuls.
EWC: ~2 gallons. I use homegrown fresh VC and it is very dense and very rich. Adding much more than that would just turn the mix to mud. Have no idea about bagged stuff, have never used it. Back when, the mix called for 2 shovelfuls of sheep manure. Haven't seen that in ages. It got outlawed in Fl and we used cow manure instead.
Lime: Healthy 3 cups of dolomite. Found that the 1cup/cf amount wasn't buffering the pH enough and bumped it up. The total of this mix ends up a bit over 2cf (~18 gallons), so a heaping 3 cup scoop works well for me. Back when, the mix called for 1 or 2 shovelfuls of 'screenings'. This was Oolitic limestone that passed through the finest screen at a aggregate quarry. The $25/dump truck load mentioned elsewhere. Very slow release. There was some 'flour' in there, but most was so coarse it took years to release. Mainly, we top dressed our lawns with it and in the mix it mostly just added some weight to keep pots from blowing over.
Anyway, that's it, my base mix. From here, the choice and amounts of amendments is pretty open and up to the individual grower, but it sure helps having a consistant base to work from when you experiment.