Facilities for keeping clean while travelling vary greatly. Guesthouses and hotels may (or may not) have showers, sometimes you may get hot and cold running water, sometimes it may be just a tap and bucket of hot water. There is no guarantee that the water you use is clean either.
Keeping your hands clean is probably the easiest way to keep healthy in some countries, although this can be hard to do if you aren’t close to fresh water and soap for most of the day. Keeping your hands away from your mouth and eyes will help (especially after handling well-thumbed bills), as well as stopping any nail-biting habit.
Some countries don’t use toilet paper in the toilets, they just aren’t designed to handle it. If you use it you are supposed to put it in the bin provided. Locals use a tap, a bucket, and their left hand. Whichever method you use, it pays to keep a bar of soap handy wherever you go.
A better way to keep clean is to keep a bottle of hand sanitizer gel with you (and use it) at all times. If you use gel you don’t need soap or water so is really useful where both of these are scarce (you can also use hand wipes but you will go through these quite quickly which can get expensive).
Sanitizing gel should be used before eating and drinking (or after touching suspect surfaces). To be effective gels require a 60% minimum alcohol concentration to kill most harmful bacteria and viruses.
You can carry a small bottle around with you (they come in travel sizes), either in your pocket or clipped to your belt or bag. These clips can be bought anywhere, for example, 
here
A far better solution is to buy a purpose-built hand sanitizer gel dispenser (shown right). These are the ones used in hospitals and contain 50ml of 70% ethyl-alcohol gel and are refillable so you can use your own gel if you prefer.
They are light and compact, are easy to carry and use, and are always on hand. You can carry them on a lanyard or clipped to waistbands, belts, bags or pockets.
They can be very hard to get hold of, however, and can be expensive if you want to buy just one. If you can’t find one then email me as I can get hold of them in the US or the UK.
You use them as illustrated below. Just flip the dispenser and push, and a small, measured dose of gel comes out, then rub your hands together for a few seconds and the gel evaporates and that’s it.
