After applying to a small studio and making a model of an axe with two pieces which meant separate UV maps. After submitting the model and textures, I was told that both the blade and handle of the Axe should be in one texture. I don't really know how to do this in Blender, so any help would be appreciated.
This can be done easily with some baking in Blender.
First, join your two object together with CTRL J.
Create UV map for your bake that include both objects.
Then create a new image for your texture bake, create a new material for it, and make sure it's selected.
Then go to the textures tab, create a new texture, and create (or link in) an image; for example, to create a new 4096² texture image for the output:
Then go to the Render tab of the Properties editor, and ensure that the Render Engine is set to Cycles (othwerise the Bake panel below will not be available):
In the Bake panel, set the Bake Mode to Textures, and press Bake.
You should get something like this. (of course it will be your textures instead of mine)
Then just save out the image, remove the other material slots and the first UV map, and you should be good!
Take your two textures, and combine them side by side in your image editor (such as photoshop).
It will make reassigning the UVs easier if the two images are the same size, and the new image is simply double the width (or height).
In blender change the texture image on both the handle and the axe.
You can do that by opening the properties region N in the Image Editor and changing the source of the image.
You will have to adjust the position of the UVs (because you changed the size and shape of the image texture.) If your new image is double the width of the old imge, select all the UVs and scale along the X axis by
Last join your two objects together CtrlJ. (If you join them before changing the UVs and texture you will be creating more work for yourself.)