Lay Down on the mat with your feet bent and on the ground. Bring your arms down to JUST ABOVE the mat - don't let your arms touch - and push up. Make sure you bring your arms out wide - making a football post. As you push the weights up, don't clank them together at the top center. That causes your chest muscles to rest. You want to keep an inch or two between the weights so your chest muscles stay engaged the entire time.
These are a great tricep workout. Your arms should be parallel and shoulder width distance. Keep your shoulders relaxed and away from your ears. Hold your weights in the air, and slowly lower down towards your forehead - keeping your arms steady and still. Make sure you keep your elbows directly over your shoulders. Don't swing them back or forth. You want your arms to be at a 90 degree angle at the bottom, then push back up to start. Your weights never touch each other and your elbows should be unmoving the entire time. Keep your elbows in (not sticking out) so your tricep gets all the work (not your shoulders).
Make sure you keep your core engaged and tight the whole time. Push your lower back down to the floor. Keep your shoulders away from your ears. I like to imagine my toddler son sitting on my stomach while I do these - that's the visual that helps me keep my core and back still and engaged.
Now you're without excuse when asked to do these moves! :)