Before an open house
Exterior
Pick up tools and toys
Close garage door
Put garbage cans in garage
Park vehicle(s) on street or around corner

Interior
Clear off all counters and table tops
Open shades and or curtains
Give the house a pleasant aroma
Set thermostat at a comfortable temperature
Set dining room table
Make all beds

What to expect from an open house
An open house offers prospective buyers the chance to view the house in a low-pressure, "browsing" atmosphere.  With that in mind, you shouldn't expect it to generate a sale, at least not directly.  What you should look for is interest expressed and requests for private showings made to your sales professional in the days following the open house.