Ideally, you will do this on a flat surface such as a work-bench.
If you’re struggling to hold the table steady and also measure at the same time then get someone else to hold the table for you.
Your cork will probably be in a circular disc shape and if it is wider than the leg you will be attaching it to, trim it down to size using your knife. If you’re concerned about the color of your cork being different to your table, now is a good time to adjust it with some paint. [4] X Research source
To help the cork get secure, putting some weight on it while the glue dries, like some heavy books, is a good option.
As the table will be putting weight down on the cork, it’s ok to turn it over while the glue is still drying. If you do this, however, don’t move the table around once you’ve flipped it.
If you level out a table that has poorly attached legs then it will soon be wobbly again regardless of how accurate your corrections are.
Check whether your surface is completely flat by using a leveling tool and seeing if the air bubble is within the middle markings on the tool. You can find leveling tools very cheaply at any hardware store.
This is because the legs are on a plane, and the plane is not flat. Sawing down these longer legs will make the plane flat.
If your table saw doesn’t have a length setting this minimal, choose the smallest setting you have. The measurements above are 1/64 of an inch and 1/32 of an inch, respectively.
Be careful not to overdo it as if you cut down too much of the leg, you’ll be left with a still wobbly table.
To use sandpaper, simply cup the paper in your palm and rub it firmly on whatever surface you are smoothing down.