1. No mixing. If you are using good perfumes to start with, you can only make things worse.
2. The best I've found is Piguet Bandit. Almost as dark and butch as the perfume. Long lasting too, and there's a great shower gel as well. It can be had very cheaply on ebay. I have not tried the other Piguet lotions, but if they are as faithful and good as this, they should be good buys.
I also like some of the Le Labo, especially oud. The Oud lotion is more the dirty part of the frag; quite long lasting too. Of course you need to like dirty musks. Too bad they don't do a patch lotion (they do an oil, it's the fantastic drydown of the frag). I also have their iris, which is not particularly long lasting, but has at times created an interesting effect post-swimming pool which I have described elsewhere.
I have not tried the Ormonde Jayne, but I have tried their oils and they are very good. If the creams are as good as the oils, it could be worth to look into them.
3- Knize Ten. The cream is a light plain leather, sort of Tuscan leather lite - nothing like the butch perfume. (The shower gel is even less faithful, a nice but undistinguished soapy floral). The Amouage creams I tried in store didn't impress me much, given their cost, but that was a quick test which may not be indicative (the Gold man shower gel is wonderful though, not as huge as the perfume, but a wonderful incensy floral nonetheless).
5-6 never as good. The perfume is always richer, long lasting etc. Still, they are sometimes good purchases that give an impression of the $$$ perfume. I have bought a few myself and have been happy. Given the price of Theorema, the lotion seems a good idea (I have not purchased it though, so I wouldn't know the specific). Bath oils are a different story, but then, good vintage bath oils cost (much) more than the perfume. Which brings me to the question: why do I seem to be the only one who collects bath oils as well?
On the topic of creams, I would like to mention the face cream and the hand cream for men by Farmacia SS Annunziata (I have not tried their for woman). One is a very rich mossy, the other hay coumarinic. They do not correspond to any perfume, but they are lovely (more so than their scents, I'd say).