You want to make it warm and welcoming. People will be coming into your home, so a certain hominess will not go amiss.
But just one piece of advice here? Don't put the priceless family heirlooms in the guest areas, no matter how perfect they would be.
Accidents happen. And Murphy's Law dictates that your most special pieces will get it first.
And you don't want to put yourself or your guests through that anguish.
If you want old-fashioned, go for the heirloom-esque. Go to auctions, flea markets and thrift stores and stock up there.
I once had a guest stumble on the way to the bathroom and knock a decorative plate from the wall and break it. She was devastated, 'fessed up and offered to pay damages.
I assured her it was fine, but it wasn't until I was able to actually show her the stack of ten just like it that my aunt had picked up for me in a yard sale that she relaxed.
Imagine if it had been the sentimental treasure she assumed it was.
Just a few more tips:
Make sure your furniture is sturdy enough for a retired linebacker to use comfortably. And keep the tchotchkes to a minimum - people need a spot to drop their own stuff.
If you get the balance right, your guests will feel comfortable enough to come back again and again.
And it's the repeat guests that are the most fun.