All Grain or Extract? For some of my own beers, I have gone to the recipe forum here on HBT and then changing some of the grains or hops or hops schedule. Pretty much any beer you can think of has been done in some capacity, so it's a matter of readjusting proportions or adding adjuncts to make it your own. Also, there's a reason people replicate those recipes, they are proven to be good beers, so you are tweaking a recipe that will give you good results and be true to the style, if you don't know what proportions and or grains/ malt extract and hops you should be using to brew that style. If you want to design one without looking at anyone else's recipes, buy brewsmith and just start building your recipe from nothing, and choose your style so you can adjust your grains and hops to be within the range of the style you are aiming for.