If your plant is indeed infested with spider mites, the leaves may have yellow blotches on them. When light falls on the leaves, you may see a silvered look or even streaks of bronze or silver.  While mites usually attack the underside of leaves, they can sometimes get greedy and also eat the upper side of leaves and flowers. Eventually, the mites will suck holes right through the leaves - providing the most obvious evidence of infestation. Even if you can't find holes in the leaves, your plant may still have spider mites, so keep an eye out for other signs of infestation. Other signs of mite damage include distortion, deformation, wilting, spotting, streaking or discoloration on the surface of the leave. If the mite damage gets particularly bad, the leaves may start to fall off. This is a giveaway sign of some spider mites. The webbing usually clusters around feeding areas. Note that not all species of spider mite will produce webbing though. Spider mites are so  small, they can be very difficult to see. However, one method you can use to confirm their presence is to take a sheet of white paper, place it beneath the plant you suspect to be infested and and lightly shake the stem of one of the leaves.  A certain number of the spider mites should fall onto the paper. They can be viewed more easily with a magnifying glass. Spider mites come in a variety of colors, including red, green, yellow and brown. They have eight legs and tend to move quite slowly. Be on the lookout for spider mites with spots on their backs - these are known as two-spotted spider mites and can be particularly hard to get rid of. There are some plants which spider mites seem to favor more than others.  In particular, pay attention to possible infestations on miniature roses, fruit trees, bananas, potted begonias, beans, mint, broad-leafed weeds, strawberries, frangipani and indoor houseplants. Be aware that the two-spotted spider mite has been known to infest over 100 different species of plant. These are the conditions where spider mites can cause the most damage, as they are thirsty and are seeking moisture from the leaves of the plant. This also means they are very attracted to anything grown under glass, including plants sitting inside on your windowsills.

Summary:
Look at the surface of the leaves. Check for white webbing on the plant. Confirm the presence of spider mites. Be particularly vigilant with certain species of plants. Be especially alert during dry and dusty weather conditions.