Good day,
You basically need a moist and warm southeasterly wind flow that extends into the higher terrains (west TX, East NM, SE Colorado) coupled with any kind of instability (such as an upper low).
With a true upslope, you really do not have a closed surface low, but a lee trough is preferred. The dryline will not play with such a setup as the SE winds extend all the way to the Rocky foothills.
Instead of parcels being forced aloft by a boundary, such as a dryline, they are being forced aloft orographically, so upslope can effectively break a cap even if dewpoints are in the 50's.
Preferably, you still want to see directional shear above the ground, even with the absence of an organized surface low.
Other exciting up-slope setups can even be in post-frontal air, where the winds have verred around to easterly in the high plains / colorado allowing upslope to 6,000 MSL elevation.
If a dryline / lee cyclone (surface low) is present, SE flow ahead of that dryline combined with upslope terrain is great for storms, such as the cap-rock enscarpment in Texas.