Among the ins and outs of mushroom food plots is the subject of scrapes. I'm going to assume that you know the basics of whitetaile scrape behavior and all about "scrape week" which for me, here in the Upper Peninsula is usually the second to last week of October-ish.
Travel corridors and hubs light up with sign, so do vegetative food plot edges and our coveted mock scrape sites, indeed its a pre rut frenzy of shock and paw.
Wherever you place your Mushroom Food Plot™, a scrape or a cluster of scrapes will occur. Matter of fact, you can use the scrapes as an indicator that the Mushroom Food Plot™ is alive and well. If you're waiting to see mushrooms and your deer have already installed a scrape(s), that's a good indicator that there is a territorial claim on that food already by those deer who can smell the sweet rich mycelium and know what comes next.
If a scrape or multiple scrapes are going to occur where we put the Mushroom Food Plot, it only stands to reason that highlighting a scrape or making one preemptively that has an advantageous shot opportunity on it is wise. "He was 20 yards broadside while playing with the rope scrape on the mushroom food plot and the wind was in my face" sounds like the beginning of a great archery story. 
Wherever you place the Mushroom Food Plot, my advice is to choose one existing scrape if possible and remove any other licking branch sites within 25+yds. Based on that scrape, I place my blind/stand at the yardage I need for the most advantageous wind, assuming of course I have good access. I install my mushroom food plot a few (5-10ish) yards away, parallel to the line of travel the scrape trail is on. In particular I'm looking for a spot between bedding and food in a travel corridor. That's it, you decide if you want to add a rope vs grapevine vs oak branches vs etc in your mock scrape.. You decide if you want to add a branch catalyst or glandular product from any of a thousand makers people swear by.
I personally seek Ironwood or Hop Hornbeam here, they seem to prefer to scrape under their branches and the deer will rub on the rough barked trunks too. If there isn't a licking branch there I simply grab a branch that's head height or taller and a few inches around, bend the branch down until it barely breaks or cracks, then I'll pull it down into a position where the deer can use it as a licking branch.
Similarly, another of my favorite tricks is to find a long tall maple, popple etc sapling, 20+ ft high and 2-4 inches at DBH, throw a rope up in that little tree and bend it down til it pops or cracks, then place it as a licking branch on a trail. The tree branch will continue growing in both cases and in the second example the long leaning arch of a tree with licking branches at chest height are irresistible. I use a move I like to call the "boot dozer" to clear a nice 2-3 foot diameter spot under my new licking branch to make sure the vegetation that could interfere is dealt with. I've destroyed a few inferior steel garden rakes fluffing up the soil in the scrape site but it's well worth the effort if you dont mind the work. One of the things I have seen and learned to mimic is that a little elevation drop in the scrape is attractive. For whatever reason I see smaller but very frequented scrapes under Ironwood Trees here where there is a bank or berm under the licking branch. It's usually on a part of the bank or berm that ranges from near vertical to 45 degrees. I imagine its just more convenient to move soil downhill for the deer. So don't think that just because a potential scrape site has uneven ground that it's not still a good spot, it might be better if there's a little topography.
Full Disclaimer, I tried one product last year. Kevin Vistinsin from the Deer Hunter Podcast makes a two part synthetic scrape system which you can find at www.DHTHREE.com. I'm not sponsored by DH3 nor do I have any affiliation. However in the interest of honesty, I will be using it again, especially the branch catalyst.
Matt