If formula feeding, invest in good containers to take out with a pre measured amount of formula in it. Tommy Tippee Closer to Nature bottles have a little thing that goes inside the bottle so when you want to make it up, just screw off the lid, and tip the formula in. Will definately be getting those for next bub.
I'd think my biggest tip, and biggest regret as I didn't follow it myself is: If a family member or friend is doing something with your child that you do not agree with, whether it be harmful or not, say something. It doesn't have to be nasty but if you don't get on top of it right away, they will continue to do so, not knowing you disagree and then it's harder to break habits. E.g When DS used to fall down at home, he'll make a few noises then get up and run off and play (unless he is really hurt, then we pick him up and comfort him, but we know the difference) however, when he is at my parents place, he'll fall down and whinge and whinge til the cows come home, knowing that my mum will pick him up. Now I pretty much have to yell at my mum so that she doesn't. We giggle at him at home now when he does it, so now he giggles too. We didn't want a sulky kid.
Thats all I can think of for now. Will update later if I think of more.