1. Tech gear. Try to take as little technology with you when you go: not only can recharging it be problematic, but unless you keep it close, sometimes security can't be guaranteed. If you have a smart phone with the ability to have speech input, load up a personal GPS app. If it can read USB memory sticks or cards, try to get hold of guidebooks before you go and get a friend to read them onto it.
2. If you're a braillist, try to get copies of any basic guides BEFORE you go - very few museums have braille guidebooks available, and those that do have copies which are usually very bulky, out of date and may be illegible through use.
3. If you have an expert guide with you, they might be able to persuade a sympathetic curator or museum attendant to let you feel some of the artefacts - take a few pairs of sterile surgical gloves for this purpose - this will save any contamination of the artefact and show any attendant that you are a bona fide blind person. It might be helpful to bring a few hard copies of proof of registration while you're at it!
4. Canes and tips. If you use a guide or a long cane. try to get hold of a pencil or pear shaped tip (or two). A rigid tip might require a bit more concentration to use, but rotating tips and Egyptian sand do NOT mix. If you have to use a rotating tip, take a bottle of WD40 or other cleaning agent with you when you walk in sandy areas - dry sand clogs up tips very quickly.
5. Always keep cash to a minimum wherever you go, and your purse or wallet should be concealed. If you wear a watch, get a cheap tactile wind up watch through your local supplier: not only will it be no real loss if it goes walkabout, but talking watches are sometimes very difficult to hear in the high volume crowds which you will find at most locations.
6. Get a pair of anti-glare wrap around sunglasses, to wear over any glasses you need - or even if you don't wear glasses normally. Not only will they offer much needed protection from the sun, but they will prevent fine sand grains getting in your eyes and damaging any contact lenses you might be wearing.
Massive thanks to Jim for these useful tips