Any at home tricks for subframes?

Put jackstands under the rear axle housing and under the k member. I've done this on 5 T-Birds my 2 mustangs 3 friends mustangs and a 63 comet and all turned out very well. Since youre already under there I would take off the controll arms and reinforce the torque boxes by welding the seams. You may consider also installing a driveshaft loop at the same time. I weld mine in and weld it to both subframe connectors, making a giant h brace out of the subframe connectors and the loop.

Buy/use 2 pairs of ramps ...

If you can get a jack under the thing, jack it up until you can slide the ramps under the tires. For other repair jobs I've used steardy concrete blocks to set the tires on as well.

Definitely weld around the perimeter of the ca torque boxes while you're under there