Lunge with the tack on. I do this even if I'm not going to ride (haven't bought a circingle yet). I made a little strap with a clip on each end (you can buy these already made) and I clip each end to a stirrup, it crossed over the saddle. You can twist up the reins and run the neck strip through to keep them out of the way. I lunge just on the line, then add the side reins and lunge with that. The side reins can go from bit to girth buckle, that gives me somewhere to clip the side reins. This is just to remind my new horse to give to bit pressure because she's green. Then I let the stirrups down and run a long line from each, through each stirrup and one goes around behind her rear for ground driving. The saddle helps me to have somewhere to attach these items during warm-up. Then when I want to ride, I just tighten the girth and get on. Easier than going back to the barn to tack up.
It depends on how I feel that day...really! Sometimes I just tack her up and do some ground work, get on and go. Other days I will do a bit of groundwork, saddle up, play around on the ground some more, and then ride. Some days all I do is ground work, like today after work I snuck out to the barn before it got dark, and did some simple stuff just to get her worked a bit.