Classic one that I hate doing for my oldest... taking crusts off bread. She has sensory issues and needs thing to be the "same" texture throughout a food item- so she doesn't like crusty food on outside (goes for meat too!) She can't even chew up carrots and swallow them. Anyway, I do it b/c it gets more food into her and less waste, since she isn't the best at getting up to the edge of the crust. (And my youngest daughter is totally fine with crusts and doesn't care at all, so at least I haven't spoiled both of them!) But I must admit I have moments of totally resenting that I have to take the crusts off her bread!
For my youngest, I often give her a break on our family rule that you carry your own plates to the kitchen. If it's something that she won't spill all over the place, I encourage her, but if it's a cereal bowl with milk in it, I just go ahead and do it. She's really bad at not spilling! Also, I still buckle her in in the car... she's in a booster seat still and just can't seem to click it in, she's not a very strong kid I guess!