1 Right from the start of the track-making process, religiously sum your master output to mono on a regular basis to check for mono compatibility.
2 With panning less is often more. Subtly pan your drum buss two degrees in one direction, and your bass by the same in the opposite direction, to separate them ever so slightly in the mix.
3 To make your main chorus or drop section more intense than the previous section, use automation to increase the width of key elements. Or, automate send levels to push parts harder into reverbs and delays.
4 When layering claps and snares, pan out the hits by varying amounts to create a characterful, spread-out stereo effect.
5 Use a reverb with a mix control for blending between early and late reflections, then isolate only the short early reflections before tucking this almost-imperceptible dimension of width under the main sound.