Trapp

Hey man! So, from my experience with trying (and failing...) to mod textures, I found out the starting point for the body is usually 512x1024 for an 1X texture, with the head being a square 512x512, hands and feet 256x256 and the genital area (correct me if I'm mistaken) 256x512.
To turn your textures from 1x or 4x to 2x, simply multiply or divide by 2 the image resolution to achieve your desired results! If you own Photoshop, here's how I do it.
- Open image on Photoshop
- Go to the Image tab on the top of the screen and choose the option "Image Size".
- The dimensions of the pic will appear there. Depending on the resolution of the image, you should either multiply or divide the highest number by 2. Multiply if you're editing a 1X texture, divide if you're working with a 4x.
And that's it! Any decent photo editing software should have an "Image Size" or "Resize" option that allows you to change the resolution of any picture without warping it. Now, for an extra tip, 4X body textures should be sized to 4098 pixels at their height, so work from there. The cheat sheets for proper resizing go as follows:
4098 > 2048 > 1024 > 512 > 256
Depending on what texture you're editing, these are the values to edit, so it's either double or half of the largest number in your textures. Hope that helps!