If your soil is very sandy, you'll need to keep a close eye on watering. Unlike loamy soils, sand doesn't hold water or nutrients very well and water-loving plants can suffer. There is a very easy way to determine the moisture content of sand. It does not involve digging around in the sand with your hands. You won't even need to touch the surface of the sand if you don't want to. You'll only need one special tool; but this is sold in most garden supply stores and many inexpensive models are available.
Purchase a moisture meter from a garden supply store, online or offline. These vary greatly in price but you can usually find them for under $20.00.
Remove the moisture meter from the packaging. Insert batteries if it is battery-operated.
Push the prong/s of the moisture meter into the sand, or follow the label directions (most meters simply stick in the ground). Wait for the amount of time indicated on the label. It won't take long; usually the meter will give a reading very quickly.
Repeat the procedure for another area of sand a few feet away, if you choose. The amount of moisture can vary greatly from one area to an area a foot or more away.