get a bag or two of the various soiless components and mix batches to meet the needs of the plants you are potting up, vermiculite is mica,good size bags are available from insulation companies cheap (they look like pills of tomato worm poop)a good additive is the disiccant crystals that hold and give off water slowly. course sand, shreaded leaves & pine needles, ground corn cobs, compost, charcoal, pearlite, peat/spagnum, crushed egg shells, coffee grounds, fines from hardwood mulch (that dusty looking stuff) the supply is endless. greenhouses tend to be dry or wet, again mix what works best for you.

Depends on what you are trying to grow and where.

Containers:
Tapla's mix is hard to beat for long term plantings. I have used coconut husk chips (CHC) as a sub for the pine bark in his mix with very good results.

In any event, a large particle mix is needed for long term plantings: more or less 4 parts pine bark, one part peat, one part peat, micronutrients, +/- dolomite depending on pH requirements.

Two excellent additives, one I have tried, one I have not. Turkey grit is good for succulents, other plants that need even faster drainage. Helps to weigh down pots, too. Turface MVP is a fired clay product used on turf fields. Holds something on the order of its own weight in water. Perfect particle size for this mix.

For containers, it is all about the particle size. Compost, saw dust, all that kind of small particle size stuff is not good, it raises the PWT. Regular potting soil, usually high percentage peat, is not so good.

For raised beds in the GH:
Regular soil has worked well for me, amended with compost. No perched water tables to worry about here. I have lychees, guavas, heliconias, starfruit, pomegranate, bananas, all in the GH beds year-round for going on 4 years with no troubles.