Targetbuttons will add a menu of up to six buttons you can click once a target is selected to invite, follow, whisper, trade, duel or inspect. You can choose to only display some buttons, or all. You can change the sizes and spaces and layout and move them around.

Personally, I’ve placed them above my target frame.

The unit frames, by the way, are customized with AG_Unitframes (I’ll get to that another time.)

Targetbuttons is "out of date", but it works fine.

Type /tbopt to configure this mod.