Your mandrel operation should follow you sizing operation if you're using something like one-shot or imperial die wax. That is, assuming you tumble then clean afterwards.
If you use graphite powder, I can be done right before charging the case with powder if you wanted to. If you don't anneal I wouldn't really bother, the spring back at a certain point can't really be overcome and it just reverts back to the sized dimension.
Sinclair/ imperial graphite lube and application media are what I use. I have also used Molybdenum powder with the application media.
I have, however, recently started using imperial resizing wax instead of spray on lubricants. So, I use an bore swab 1 caliber undersized, rub my fingers in the wax and twist them lightly around the swab to permeate the fibers. Then I run the swab in the unsized case neck with a twist before using any excess at the case mouth to lube the rest of the case. I reapply wax to the brush about every 3 cases, which, admittedly leaves a little too much on the fingers for resizing, so I wipe the excess on the fingers on an old slick lens cloth. I have found wiping a case with said cloth is actually a decent application method now, Lol.
I'm sure, like me, many of you are curios from time to time how others process goes.
General process
If covered in filth like mud or something I start with tumbling in walnut. Otherwise:
-Deprime with decapping die
-Clean primer pocket with rcbs prep station
-Into the Amp annealer
-Lube
-Resize
*** when using my SAC bushing die with SAC expander mandrel I skip separate mandrel operations and lube inside case neck when luring the case.
-Neck lube (if using dry lube)
-Mandrel
-Tumble in rice 2 hours (outlet timer)
-Remove tumbling media
-Check primer flash hole for media
-Trim, chamfer and deburr if needed
-Prime
-Charge
-Seat bullets
If I'm not shooting right way or soon after loading, I seat the bullets long by 30-50 thousandths for storage; and then, before I head out to shoot, I seat them to length.