Women: Clench the muscles you would use to stop urine flow. Hold for 3-5 seconds, and release for 3-5 seconds. Perform 25 reps, 3 times a day.
Men: Place a dry washcloth over your erect penis and clench your muscles to raise the cloth. Repeat until this becomes easier, then graduate to a wet cloth for more weight.
Kegel balls with inner weights are the simplest toys for beginners, just insert and go! The inner weights move when you move, causing the muscles to contract. These toys can be discreetly worn during everyday activities for long periods of time, and are so comfortable and fuss-free, many women forget they are working out!