Draka - we use three point slings on our long guns; when they run dry of malfunction we just "sweep" them to the weak side while drawing our sidearms; the sling does the rest for us.
WRT "tactical" reloading ala the IDPA reload, I'm not a fan. It's a specialty skill that should only be used when you have a definite "lull" in the fight; not something you should be doing if there are still threats active in the area. Better to get VERY fast at reloading from slide lock ("Emergency Reload" for our agency) or just topping off with a fresh magazine ("Tactical Reload" for our agency). Neither of these skills requires any real thought, or any fine motor movements/juggling that is unlikely to be "do-able" in a gunfight.
Threegun's reload drill is as good as any; "shoot two, reload, shoot two repeat" will teach you the muscle memory you need to get fast at reloading. Once you've got the motions down, I like a more advanced technique wherein I load five or six magazines with anything from one to five rounds, put them in a pocket, and randomly load one, then put the rest in mag pouches. What this does is take some of the "game" out of the reload drill insofar as you don't have advanced warning of when you're going to have to reload...
Regards,
Kevin