I always lose air from a tyre when I try to use one of the type of pressure gauge that depress the pin in the valve as the gauge is attached, so I have to pump it up whether or not the pressure was already correct. It seems logical to me to have a fitting which attaches to the valve, with a button or other device that then presses the pin for a reading. Does such a gauge exist, or are there other types of gauge that do not present this problem to ham fisted users like me?
You can get valve caps that indicate tyre pressures on them in a Red/Amber/Green state. They are available in a range of different pressures so you could replace your normal valve caps with them which would stop you even having to remove them to check the pressure.
You can find more by searching for Valve Cap Pressure Indicators