mastering w/c is mastering draftsmanship. Try all paper including bond paper, (wrinkled as well) everyone has a paper,cold pressed or hot,rough or smooth. Read Watercolor Fares Forth
'hara Look at books on various watercolor artist. Try to use color from 20th century masters..Klee, Matisse,Bonnard the triumvirate of interesting colorists. Try various amounts of water with pigment,see Marin he gives simple instructions ..similar to this. I believe in studying the formal possibilities and then developing subject matter.Many just copy and follow the direction of the big watercolor competions.Most transparent only exhibitions eliminate experimental work because they limit the drawing to pencil work.The British were using various drawing implements in the 18th century..quill,reed pen,metal points. Canneletto would have been eliminated under ther rules.