Drum fills can change a lot depending on whether the drummer is left or right handed, and which side the drummer likes their vocal mic to come at them from, so leave that kind of thing till last to set up.
Getting the drum wedge high up and off the stage (on crates or any other kind of “stand”) so it’s closer to their ears, means using less electrical energy, and reducing the overall level on stage.
Side fills- these are often old FOH PA that have been redeployed as side fills when the main PA is replaced. Side Fills have as many disadvantages as advantages – if the vocal is right for the singer in the centre of the stage, it’s likely to be ear-splitting for the musicians on the side of the stage!
There are ways around this, by flying the side fills, for example, or using low profile fills which then do not drill directly into musician’s ears, and help with sight-lines.
Many bands now use side fills, these also have their own advantages and disadvantages. Justin discusses some of these issues.