You can buy aerosol flux remover that I found quite good.
I found that for multi leg ICs, tinning the pads lightly (not too much solder), then tacking 2 corners, a good way to start. Then just use a clean tip (no solder) and push down on the top pad bit of the leg briefly to make the connection for each leg. After the tinning I normally apply flux, with a flux pen, to the tinned pads.
Simple components(which includes 3 leg BJT or mosfets) I tin one pad, hold the component in place and reheat the solder, I then solder the other side(s), adding solder to get a fillet between pad and component end. I then re-solder the first side. This allows the component to be flat against the PCB.
In all cases it is best to use as little solder as you can get away with.
After completing the population of the board, I clean it with aerosol flux remover.
I, like Steve, use a flat tip about 3mm wide for all my SMT work, but be sure to have some de-soldering braid available.
For most hobby purposes, I found 1206 to be perfectly acceptable and it doesn't strain my old eyes as much.
The most difficult items are ICs like 80pin TQFN packages - mostly it is difficult lining them up properly and it is important as tolerances are small on these packages.