I have some red fox gland saved up . Does anyone have a simple recipe for a good gland lure?

I imagine dropping those glands in some good quality urine and letting them sit for a time would be a good start

No expert of fox glands but here's my thoughts.
First clean all the meat and faces of glands then trim hair and most of the fat away (a little fat is ok). Next grind. Add some fox urine then age. I like to age half the batch a month or 3 depending on temperature (fresher type of glands lure) then age the rest at least a year 2 is out of the question. Both bases are usable as they are or you could spice them up with a touch of lovage oil and or asafoetida. I'm sure theirs other side odors you could use just have to do some experimenting and testing.
Ps age out of the sun light.

I think making gland lure for any of the canines is pretty similar. So while I've not done fox, I've done coyote and wolf. There are lots of variations depending not only on what you put in it, but on how long and at what temperatures you age it. And many of them work to one degree or another. Yes sir has good advice, I'd start with his "recipe", I've had very good luck doing exactly that, with the only additives being SB when I wanted to stop it and glycerin (unnecessary if you aren't going to use your lure in freezing temps). You can use it at any stage of the process also, I've used it the day after I ground it up before and been successful. I prefer to age mine at a constant, mild temperature (currently aging in a controlled room of the shop that is kept in the low 60s year round), but you can age at high temperatures or wildly varying temps (like outside, sitting on a tin roof) and get usable product. The odor does change, depending on how it is aged, so you'll have to decide what you prefer.