I've only done at home parties since the kids were about 4. I invite a few friends and for a 6 year old I prepare a few games (pass the parcel, pin the tail on the donkey, etc). I tend to host parties from 4pm - 6pm so I include an evening meal which is usually mexican with crispy chicken so all the kids can help themselves and allow about half an hour for free play. It's usually enough, they love the old fashioned games and just a chance to play outside of school. My older boys don't want the games any more so it tend to be dinner and a movie, or dinner and a sleepover for even smaller numbers.
Usually the parents don't stay, and I never assume I will be staying for a kids party unless invited to.
ETA: Make your own pizza parties tend to go down well too, and last time I had a craft task of decorating their own mug to take home instead of a party bag which was popular with all the kids.
