Can I make something composed only of Creative Market products?
Yes, this is permitted so long as what you create is an End Product. End Products must be significantly different than the original Item and require time, effort, and skill to produce. End Products must not be used or sold in a way that is directly competitive with the original Item you purchased. End Products must not redistribute the original Item to any third parties in a manner that allows for the extraction of the original Item.
So, for example, you may employ various methods and skills to create a significantly different design, including adding textures, using Lightroom presets, adding unique hand lettering or illustrations, adding graphics or patterns, using various Photoshop add-ons, adding text, addition additional photos, etc.
However, you are not permitted to purchase one font and one photo and use solely those unchanged Items in a wall art design. However, you can include that photo and the font in a greater wall art design, as long as the end result of that design is significantly different than the photo and font that you originally purchased.