So there are two keybinds that I use that I think most people might find useful. The existing keybinds require alias which I think is unnecessary (or is it?).
1) Cast Exaltation on a specific target /bind e "+Hardtargetlock $$ target "target's name" $$ +PowerTrayExec 3"
I have Exal in 2nd encounter slot so I bind E; you can bind Q or R and just need to change PowerTrayExec to 2 and 4 respectively. 2) Cast Divinity Divine Glow on a specific target /bind v "+Hardtargetlock $$ target "target's name" $$ +specialClassPower $$ +PowerTrayExec 4 $$ +PowerTrayExec 4"
When you press V, you will cast divinity DG at your target's location. Again, you can change the key you bind and the encounter slot, you just need to make corresponding changes to the command.
Finally, change the target's name depending on who you're buffing and that's it.