I am at long last almost done gluing all my floors down, pretty much my entire first except for some tiled areas with big transitions to wood. Now it's time to put down the t-molding... Or, is it time to put down the base molding and THEN make the t-molding fit between the base molding? Or, do I put down the t-molding and then notch the base molding to fit over top the t-molding? Help please!!!

In the past I always installed the base and tight fit the t-mouldings to the base. Recently I have changed that, ( All I seem to get lately is tweaked out T-mouldings ). I'm installing the T-moulding, toenailing a nail into the wall, ( to keep the ends down), notching the base to fit over top of the moulding, running a piece of blue tape ( where the base sits on the moulding, running a little white caulk, and pulling the tape.
Works out great on those tweaked T-mouldings, and looks like it's growing out of the base. Ofcoarse I save the straightest section of the mouldings for casing transitions, ( Last install I actually had to chisel the casing to slide the ends under, ( that darn LL ).

Thanks! That seemed to be the best way in case the t molding expanded, but how do I notch the base molding?

Other questions: I was going to glue down the t-molding, but a video I watched showed pushing the t molding into a plastic track first and then gluing that down. Do I need to do that? What does that do for me?

Also, I going to try to put up the same base molding I took down to install the floors. What is the process for that: do I patch and paint them and then put them up and then touch them up? Do I put them up then patch and paint them? Or something else?

Thanks again!

You won't get any expansion out of a T-moulding, but that method works good for holding the ends down.
To notch the base. I'll take the end profile of the T-moulding ( minus the leg) , and mark it on the baseboard with a utility knife, then cut it out carefully on the table saw.

Tracks are nice to use, but most the time only available for Laminate transitions. For Hardwood transitions just glue the leg down with some PL adhesive. You may want to weight it down over night, ( depending on how nice it seats ) . Alot of times I'll use a 24 ga. wire nailer, and tack it down so it sets tight & flush on the wood, while the adhesive is setting.

Typically I remove the base and clean it up, ( rip it to size if needed ) . Customer has the option to paint it while it's off. I re-install it, caulk it all in, customer does paint touch up.