1: Hydro is easier than soil, if you go simple. Lucas Formula w/ Maxibloom + bubble buckets are pretty hard to get wrong. Lucas Formula + Hempy Buckets are even harder to get wrong. Soil is dirtier (heh) and harder to correct nutrient problems in. If you have nute problems, you can always just dump the rez and re-fill.
2: Bottom heat is the secret to fast clone rooting and high strike rates.
2a: You don't need a heating pad and a thermostat -- just get a plastic bin smaller than your clone tray and a 100-ish watt, thermostatically controlled submersible fish tank heater. Fill the bin half full of water, set the heater to 85, drop it in, and put the clone tray on top.
3: Holy crap do DWC plants get big, quick.
4: Evaluate additives through side-by-side grows with a control, or by reading side-by-side comparisons from people who're doing it right. (If the plants are all from seed, they're doing it wrong.) Everything else is hearsay and should be regarded as potential snake oil.
5: Clones (and moms) are insurance and the cheapest source of new plants.
6: Sometimes smaller's better, particularly when you can cram 16 plants in the same space you can grow one huge bush in.
7: Naturally cool basements are awesome.
8: Read lots of grow logs, so you can learn from other people's mistakes -- and triumphs.