Comparing your children may create animosity among them, as they may interpret you saying, "Why can't you finish your peas like Tommy?" or "See, Vicki is reading quietly," as you favoring the other child.
Point out their unique qualities
Be sure to point out the unique differences in their personalities to show them that you don't want them to be exactly alike and that you love each of them (equally!) for exactly who they are.
Sibling rivalry can stem from jealousy or insecurity, so make sure to give your children the confidence they are seeking.
Spend some one-on-one time with each child
Give each child some of your undivided attention each day. Work on a puzzle with one child while the other reads a book or help one child get set up with an activity before you nurse or rock baby.
Praise them when they resolve a conflict
When you see a conflict arising, give your children an opportunity to try to resolve it themselves. Even if you need to step in to completely solve the problem, praise them both equally for working together to try to find a solution.
Nip roughhousing in the bud
Yes, kids love to wrestle and roughhouse, but take note of what's real play and what might escalate into an out-and-out brawl. Separate your children before they get too heated. Give them some time to calm down and after regrouping talk about the issue and resolve it together… before someone gets hurt.
For the record, my children are very loving… for the most part. My son dotes on my daughter when I least expect it and my daughter follows my son around like a puppy because she idolizes him so (the very reason why many tiffs start, in fact). There is hope for them. Oh, and my daughter's orthopedic surgeon says her bone regrowth is coming along beautifully.