I use it every time before polishing, then in between polishes as needed.
I usually polish my shoes every two to three weeks with the following process a)wipe them down with a soft lint free cloth or shoe brush, if there is visible dirt that is not coming off this way I'll use a little water, then let the shoe dry thoroughly. b)with a soft lint free cloth apply a very light coating of Saphir Renovateur, allow at least 5 minutes to dry, brush off the excess with a shoe brush. c) apply a light coat of shoe polish or shoe cream (depending on the shoe) allow to dry (per manufacturers specs), brush off with shoe brush, buff with polishing cloth.....if I really want a high shine i'll repeat step "c" with a wax based polish and do a little spit shine. In between polishes if I start to see scuffs, creases, marks, ect i'll apply a little Renovateur to the area, let sit 5 min, buff off. Oh, and I bought a pair of used AEs off ebay a while ago, they were not in bad shape, but clearly used, I applied a decent coat of the saphir, let them sit overnight on shoe trees, buffed them, and they looked a million times better. I'll make no claims that this is the best way to take care of your shoes, but its what I have been doing for a little over a year now and I have been super happy with the results.
Edit: I have used it on a pair of natural colored oxfords and a pair of walnut colored derbys, both from AE, and did not notice any darkening
Last edited by Me27; January 10th, 2017 at 04:33 PM.
I've used it as a cleaner/conditioner prior to polishing all my shoes since I got it about a year ago. I definitely don't do the brush/clean/polish routine as often as I should. It definitely takes up a lot of the dirt and other mess.
I haven't noticed it to darken anything, although I haven't used it on my lightest color shoes, walnut 5th Ave.
I use it before polishing and sometimes on its own (such as with cordovan or pebble grain), basically as a substitute for AE conditioner/cleaner. I haven't noticed it to darken any of my lighter leathers (walnut / tan).
I use similar to what @Me27 does, except I typically let the Reno dry for longer than 5 min (more like 15-30) so the leather can soak in as much as possible, since I'm mainly using for conditioning purposes. I also use a relatively small amount overall and focus on areas with creasing, scuffs, etc. the most.
I use a cloth to apply it the way Me27 describes. I used to do it every month but since September (moved state/house and had a third baby), I have only done it once. I still have some AE polish which I use on some shoes instead of Saphir.