Crickets need access to fresh water which can be done several ways. As discussed earlier, you can give your crickets fruit and vegetables that have a high water content and they will suck the moisture out. This is a good option for pinhead and tiny crickets who can drown easily but make sure you replace them regularly as they will dry out quickly.
A good way to provide water to bigger sized crickets is by putting a damp cloth in a plastic bowl. Make sure that the cloth you use is food safe and that it remains damp but not so wet that there is a pool of water at the bottom of the dish as your crickets may drown. You will need to check that the cloth is still damp about every 12hours however if your crickets are kept in a warm-hot area it may need checking more often as it will dry out quicker.
Another option for providing water is using a small bird gravity waterer. These are a good option as only a small amount of water is able to come out at any one time which can help to avoid drowning crickets and you wont need to check if it has dried out as often.