Koors8672, I'm a fairly new Dexcom user too, and I found some videos on YouTube that showed exactly how to insert the sensor into your arm. I was also impressed to learn that you don't have to change your sensor every week, as Dexcom suggests. So for the past few months, I've been using my arm exclusively, and I leave the sensor in until the adhesive is about to fall off. I also apply Skin Tac liquid adhesive, which really extends how long the sensor will stick. So (1) arm, (2) length of service, and (3) Skin Tac — these are all things Dexcom doesn't tell you, but the diabetes community does.