Good point Yoyo!!!! Being extra nice even when they are mean can be very friendship-building... and even a little fun! It's like trying to get a cranky person to let go of the chip on their shoulder. When my husband and I were in divorce I'd still do nice things all the time. But the main thing about doing these nice things is to not have expectations and present them in a way so the spouse doesn't feel like you are expecting something from them. That way the nice things don't backfire and make it look like you are wanting more than they are willing to give... while they are far from ready for that.
For example, I love to bake!!! (Yes, there are thin woman who love to bake!!!), and I used to make cookies and things. During the divorce I'd put extra homemade cookies, muffins or whatever in baggies and either give them to my husband when he dropped off the kids or leave it with his mail. I'd always explain or leave a note saying how I happened to bake a bunch of cookies, we couldn't possibly eat them all and I thought he might enjoy a few. I'd rather share them then throw the extras away. Even though it took time, I think it was little tokens of good will like this that helped him see me in a more positive light.
In the beginning he wouldn't except them or would just leave them at the house. Eventually, once time had passed and some of the really intense anger had diminished (and he didn't feel threated or like I was "trying to get back together with him") he would accept them. He didn't thank me, but at least he took them. Then eventually, as more time passed, he finally got to a point where he would thank me. I learned to not expect that. So when he did I would be very grateful and tell him I was really pleased he liked whatever I had left or given him....
So... in your case, if you were to drop off some over the counter medicine or whatever... you could say, "Hey I just happened to pick up two bottles of this the other day for the kids," (Even if you just bought it an hour ago!), "I don't think they'll need the second bottle right away so if you could use it please go ahead and take it.... if not that's okay too...."
There is no arriving, ever. It is all a continual becoming.