- you need to make sure that all mould lines etc have been removed because this method will show them up like motorways on an OS map;
- the whole point is taking paint off a figure so you need to make sure you have a solid undercoat.
- add more paint and wipe off again;
- let the whole thing dry and apply successive thin oil washes until you reach the desired effect.
The wiping 'tool' can be a piece of old T-shirt, kitchen towel, kleenex or bog roll. Any paper product will leave bits on the horse, particularly around the main/tail/ears etc, anywhere the casting has parts that will catch. Cloth can also leave lint; there's no really 'clean' answer, so don't go cutting up a perfectly good T-shirt. It's also an idea to use a disposable vinyl glove on the hand doing the wiping cos it can get messy. Keep a slimmer piece of the wiping cloth or paper to do the job between the legs and other difficult to reach places.
- Horse and Musket period cavalry units tried to colour match horses within squadrons, if not regiments,
- later Napoleonic French cavalry regiments would not win the Horse of the Year show,
- try to curb your enthusiasm for the more exotic horse colours (the bulk of regular military horses were/are bays or chestnuts),
- same with horse markings. Some horses actually don't have any (!) and those that do tend to have a modest representation.