Find that aquascaping is like a steak, everyone has a way they like and most think that you're doing a disservice if you do it any other way. So do what you think you'll like.
That said some things I like
-I actually like more negative space than filled space, having separate structures can give fish the feeling that they have a "region" which is their's to hang out around, negative space doesn't always have to be lack of any rock structures, having lots of caves or arches does a similar thing. I understand smaller tanks do have more restrictions (one reason I don't like smaller tanks
)
-Depending upon the corals you plan on having you may not want to go too high, if you have sticks take into account how high you want them to grow it may take years and years but it might be nicer than having a minicolony that gets no bigger due to pruning, if you have encrusting or plating corals in mind this is less of an issue. So having a tall pillar could be fine if you plan on only having monti caps on them or something, where as your acropora hangout you want to make sure you allow room to grow vertically which is really hard to do when setting up a tank because that takes time
-I also like to make sure I can get a hand with a scrubby pad between the glass and the rocks without touching ideally being no where close to touching, cleaning the tank is essentially and I have experienced with getting punctured by stuff on rockwork, it ain't fun.
-Also while I like the idea of using products to secure rocks, emarco stuff, etc, (and in some cases it's absolutely necessary if you're doing gravity defying maneuvers) having stacked rocks give you the option to pull a single rock out if you find things are getting out of hand, whether it's coral height, pests, etc. Mind you you have to be more careful about stacking securely in this way.
