This is an unusual tool. One of the most useful and the cheapest on the market. I have used them for many years, almost 45 I think.
My students often complain that marking gauges are difficult to use. They are not, but they can be at first. The problem is that people spike them down into the wood and then and they then follow the grain line. Trailing the point on the surface lightly is the secret to gauges. But here is a great solution I am sure you will like.
Firstly you will need to find an old countersunk screw with a slotted (flat US) head, unless you happen to have a couple of boxes lying around. I avoid cross (Philips) heads on my furniture because they are so utilitarianly ugly and you can’t line up the slots the same.
The edge of the screw must be filed to a consistent cutting edge following the round of the screw head.
Screws are machined to remove a sharp corner from the countersunk head as you can see above, second image.
Filing the rim at an angle as shown creates a cutting wheel effect (without rotation) and gives good precision to the hand. You can also see the position of the edge for accuracy and it is effortless to use and guide. The screw is also easily resharpenable with a flat file or diamond plate and diamond plates give a superfine edge if needed. Simply hold the palm gauge in the hand and rotate the screwhead on the plate.
To use the gauge is simply a question of setting the distance with a rule or to a thickness and then running it along the wood as you would any gauge. I use it as follows for setting hinges:
Set the first setting to the inside of the hinge knuckle as shown by simply turning the screw with a screwdriver.
Set the second setting to the thickness of the hinge flap as shown by advancing the screw deeper into the gauge with the screwdriver. Of course these gauges are cheap enough to produce in twos and threes.
That’s how the gauge works for a marking gauge. More to follow shortly on using it and how to recess hinges!