Lucca,
You'll have to experiment until you find what works for you. I use orange concealer, applied with a small stippling brush. I work the concealer into my skin by stippling and rotating the brush left, then right to work it into the pores. I use only enough concealer to to neutralize the blue beard shadow. Apply it in layers until you only see orange and there is no blue. Then I let the concealer "cook in" to my skin for about 15 minutes before covering with foundation. The cooking in step is pretty important, so don't discount it. Cooking in simply means that you are letting the concealer settle into your pores. Then, I use full-coverage foundation, but I apply it in very thin layers and stop as soon as the orange shade disappears. I have found that by applying foundation too heavily, you can end up with a shadow that looks much like beard shadow, kind of defeating the original intent. The bottom line is to use only as much foundation as is absolutely necessary. Finally, carefully blend your foundation so it appears uniform in shade and looks evenly distributed across all of your facial features.
Practice, practice, practice should be your mantra, because perfecting makeup application isn't easy. Best of luck,
Sally