Here are some tips you may want to try:
Use H/V Wash for sandy textures with not equal lighting
The textures with small details, like texture of sand, paper, fine wall can be easily created using H/V Wash Effect instead of Normal and then trying to match the non equal ligts.
|This is a great texture, however the non equal lighting would make it difficult to make it seamless.||Whatever you try the chances that you will have hard time to fix the borders with ordinary tools are pretty high.||However the H/V Wash in the Tile Preparation creates almost balanced texture.|
Remember H/V Wash textures are in fact 2 times smaller than the size you selected.
Use Sparkles and Flare to create amazing textures
You should use smaller settings in Flare. because the bright corona may create the visible tile borders.
|Start with black background||Put some small Flare||Add sparkles|
Use Image Nozzle with texture or Clone
Sometimes you need different color of Image Nozzle. You can experiment with the Texture. Just select any texture and move the % slider to get the right mixture. Also you can try Texture Clone.