Building Your Own Recipes

I wanted to start creating recipes, and while I am also looking for any help getting started, I also had a question about how I should go about for testing recipes.

Does it make sense to "microbrew" it and only make a gallon for taste and then if it is good, produce it with my 5 gallon setup? Or should I just go for it with the full 5 gallons every time?

With the above question, is it just as simple as scaling the recipe up to a 5 gallon size or is that harder than I will think it is?

Just trying to get my bearings as I make this next adventure into homebrewing!