I'm not a fan of putting a high importance on the recipe (as far as ingredients). The recipe is important for sure, but I find equally so, or even more important is your brewing process (wort preparation, through to fermentation and packaging). There are some ingredients that play better together than other combinations - absolutely - just like in cooking. As long as the ingredients are in balance, the beer will turn out great if you use good technique.
As far as evaluating a recipe, it is relatively simple.
As far as grains go, the key is understanding what adding a specific grain adds to the beer. There are lots of fairly accurate descriptions of what flavors, body, etc. the various malts add to a beer. The only tricky part (and it is not that tricky) is knowing how much of each to add to meet your goal. Check a recipe to see if it contains a large amount of a particular malt - mostly this applies to specialty malts. More is not always better. This is a clue that the recipe might be out of balance (too much a particular flavor - unless that is what you want)
Hops are a bit trickier to really get a good grasp of as there are so many with such a variety of flavors. Here I would say the most important thing is discovering if there are any hops you love, and any hops you hate. Then avoid, or use those. Some combinations are better than others, but I have not really met any that were bad - except for the few hops I know I don't like (and that is style dependent). In evaluating a recipe, just ask your self, are the IBUs in the range I like (for the style), then do the amounts of hops used (if used) for flavor and aroma fit what you like. This will take a little brewing experience on your own to figure out what you like. There are no calculators (yet) out there that can predict how much flavor and aroma you will get from a specific hop addition so it initially is a bit of trial and error - but a fun series of experiments.
Not part of the ingredients, but fermentation is very important and a bad fermentation can ruin a perfectly good recipe. Warmer? Colder? Primary only? Secondary? All these, and more, have an influence on the flavor of beer. There are some general guidelines out there for how each of these affects the flavors. Choose your fermentation conditions accordingly. I can't over emphasize how important this is.
The real trick then is when tasting a beer, to be able to decipher what parts of the flavors are simply from the ingredients and what parts are from how the beer was made. This is a true art! And this is probably more important in evaluating a less than stellar beer. Was it the recipe, or the process? Say the beer tastes thin. You look at the ingredients and see (beyond the appropriate amount of base malt) a 1 lb of wheat, and 8 oz. of crystal 60. This in theory should be plenty of ingredients to have good body, so in this case the process is likely to blame
Once you have an idea of the problems then you can address them. There are two ways to do this. Keep the process the same, and add more (or less) ingredients to correct what is lacking (or too strong). Or, you can keep the recipe the same, and modify the process to achieve your goal. The latter may include what temp(s) you mash at, what temp(s) you ferment at, etc. And of course don't forget the choice of a little bit of each. Tweaks to both the recipe and the process!