well I am sure by now you figured your arrangement of pictures & their  layout, but I have a very large family and I love pictures. My walls throughout my house are of nothing but portrait pictures some professional, some not. But all of them are of my husband and I & our 5 children and 12 grandchildren. They only ones that are in the same frames are our yearly xmas family photos and those are mixed among all the rest of them. They are high, low and eye level. The mix n match looks wonderful whether you have alot or not. If you like perfection mix n match is probly not a good thing, if not then it's great. Good luck and happy hanging.