I like to work with methods that are more on the "practical" side. 
I keep the tiles or sprites lined up, and from there i make sure that they connect or transision correctly. 

From there I export the pictures as PNG´s, move them to Unreal Engine 5 and then create materials that I can polish and make assets from, usually with prefabs. 

What makes this method very easy to use, is that I have plenty of controll over polish and adjustments. 
By simply make adjustments on the art directly in Piskel, I can then reimport the PNG´s in Unreal Engine and get the the changes to the prefabs right away.