A plus for the open house baby shower is that there are pockets of time for the mommy-to-be to take a rest. It's also not demanded of the host to keep the baby shower going at a good clip so that the guests don't get bored. And, the guests will be thankful that they don't have to be coerced into doing silly games.
And a bonus for guests with children is that they can bring the children to visit and they do not need to look for a babysitter just to go out. If the children are bored, they can make their leave when it's needed.
First of all, the invitation has to make it clear that this baby shower will be done open house style. That means that any guest is free to drop in during certain set hours and stay until the time is up, or leave if needed. So, some guests may arrive early and leave when everything is done, but others don't need to feel guilty that they can only stay twenty minutes or so. A traditional invitation is best for this, since it leaves enough space to make that explanation.
Next, decorating is also simplified. A few beautiful bouquets in the mother-to-be's favorite colors or her chosen color for a layette would do just fine. There's no need to fuss with balloons or streamers, unless you really love decorating.
The room itself can be set up as if for a cocktail party, since not everyone will be there at the same time. Some added plants and candles will make a cozier scene.
What's most important in this set-up is the buffet table since you need to figure out how to keep everything at an optimal temperature. If you're serving hot food, see about borrowing or renting chafing dishes or maybe just a crockpot is all you need. Decorate the buffet table with a few more bouquets, and let the baby shower cake be the center of attention. To make life easier, you can rent a cupcakes stand, and just refill the stand as needed. No need for knives or special servers.
Be sure to choose food that can stand up for several hours. Vegetable sticks, chips, and a selection of dips are always welcome. Other choices could be spicy chicken wings, bread and crackers with assorted cheese and fruit, deviled eggs, shrimp cocktail, lasagna, pasta salads, cobb salad, nuts, and olives are all great choices for this spread. Anything that can be served at a picnic or at a cocktail party (think appetizers) are great options for a buffet of this sort. Finger foods would be best since the guests can wander around while they're eating.
A nice activity for this open house baby shower would be to have the guests write pieces of advice or inspirational words on loose sheets of paper. You could have colored sheets as well as white so the guests can choose the colors they like best. Have some pens around, as well as some crafting items like colored pens, stickers, and such around so they can decorate the pages if they wish. When they're done, the pages can be dropped into a basket so they can be collected later
At the end of the shower, all the papers are gathered and put into
a memory book to be presented to the mother-to-be. It's a nice memento
to end the open house baby shower.