Boy, for a non-believer, I sure do have a lot of superstitions about Samhain; I suppose that any Time that marks an End-Beginning will acquire its due share. Many seem to be of a sympathetic magical nature, on the premise of As you begin, so will you continue. Some are just plain weird.
Forthwith:
The rent should be paid.
All bills need to be paid.
The gas tank should be full.
You should have some money in your pocket.
The house should be clean.
There should be a fire on the hearth.
All garbage should be taken out of the house before sunset. (Otherwise, you'll just be dealing with old garbage all year.)
The back door needs to be closed and locked by sundown on Samhain Eve, and needs to stay that way at least until sunrise the next morning.
You need to have these things in the house: bread, salt, potatoes, onions, garlic. (Actually, you should always have these things in the house, anyway; but at Samhain, it's particularly important.)
There should be more food on the table than can be eaten. (This for abundance through the year to come.)