Embrace surprise and watercolor will take you on the ride of your life. Watercolor reinvents itself...right before your eyes. Let the paper dance with the color. Tango, Rhumba, Quick Step, Cha Cha Cha...there is a paper to match your rhythmn.
Usually, the paint will dry lighter than it looks as you apply it. However, different papers react in very different ways,
and it's through trial and error...that you 'fail your way to the top.' Water Color Medium when added to your water...will also intensify your colors!
When I paint...I first consider the subject. That dicates the paper I will use. For portraits I use Arches Cold Press...I want a surface that allows me to work blends of many values. For florals I use smooth Bristol board...as this paper will not dull your color...you get brilliant color. For small vignettes I use Yupo. Blasting bolts of color is the name of the game. I use a fixative such as Golden Varnishes-Archival Varnish to prevent fading and frame under single-strength glass for brilliance. Buy Expensive brushes...with care they will last longer than you. The best paints are a bargain...as a little goes a longer way.
I never hit painter's block because I choose families of subjects and then I paint the fathers, mothers, aunts, uncles...you get the picture. Or I may just put a particular family of work aside...and choose another...just to stay fresh. At a later time...I just throw a dart...and where the dart lands...I start afresh.
Pay attention to the rules of color. That way...whatever you paint...it will come out allright.