She might be getting tired - does she have down time after lunch or a nap? Down time helps my ds - I either enforce him sitting down to read for 30 mins while his little sister naps or lie him on the sofa and we watch tv together. Or take them for a walk and he drops off in the pushchair.
Giving warnings helps - keeping my voice calm. So saying "ok ds I'm going to count to 3 and I'll do x". I'll check that he's heard me by asking a few times. Once I'm sure, I count to 3 slowly reminding him that when I get to 3, that I'll do it if he won't (eg getting him dressed).
Other tactics include making a joke. So if I want him to get dressed, I say I'll tickle him, pull him into my lap and tickle him while I dress him. He loves it, he gets dressed, sorted.
Things like wanting chocolate for lunch, I don't dwell on the requests. If he asks, I say no, he says why, I tell him. If he kicks off, I calmly say "mummy said no", then leave him to it for a bit.
If he wants something but can't have it because he's asked rudely or shouted, I tell him to ask nicely. I remind him how to ask if he wants something nicely.
We spend a lot of time reminding ds what he should do. So when he kicks off, I can say "ds, how do you get something?" and he can calm down and ask.
If he has a meltdown (tears, unable to calm down), I will give him a cuddle. Sometimes he needs it.
Other times if he won't do something, and counting hasn't worked then I tell him I'm leaving him alone until he does it. That can really work at times!
Losing your temper, swearing etc will make it worse as your dd will just feed off your stress, and it escalates. It certainly does with my DS so I try and stay calm. Sometimes I say calmly to ds that I'm getting cross and that can help me. Other days I end up raising my voice and it gets worse and worse.
Arm yourself with a few tactics, remind yourself that she's only 3, and that sometimes she wants a bit of control. Tell her and how her how to behave - again so you can remind her whatshe should do and that gives her control.
This isn't about her being a stroppy girl - its just her being 3.