With these GIFs and directions, you may have no problems regarding the submission of your measurements. Do keep in mind to provide accurate measurements to get Perfect Fit. If you have specific requirements for how you would like the cut of your jeans, indicate it later in the ordering process.
To get a suitable fitting, Try to measure as appropriate as possible without excessive cloth. Leggings for ladies and thin gym shorts for men work well for these measurements.
How to take your Body Measurements?