Reduce sweating as much as you can to keep your eczema from flaring up. Sweating can make eczema worse. Once you have finished anything physical, get cooled down as quickly as possible. A shower can help here.
Put your moisturizer on when the skin is damp. When damp, your skin is pulling in moisture, so it helps. Begin blotting the skin lightly with a cotton towel to get it to moist but not wet. Next, apply the moisturizer. This should be done within three minutes of getting out of the shower or bath, as that is when the skin has the most moisture.
Don't take showers which are hot. Taking a hot shower may feel great at the time, but your skin could get irritated in the process. Particularly if you have eczema, be cautious when turning the water on. Instead, shower with room temperature water. Gently clean your skin and apply moisturizer.