Most preschoolers are much more interested in friends and family they know well, most belong to play groups too, and you should be able to formulate a modest guest list from their play group, so your preschooler will be at ease and entertained.
As always, try to plan preschooler parties around nap time.
The last thing anyone needs is tired, cranky children.
Also, if you plan a late morning, after breakfast party, giving parents who do not plan to stay and help out, a specific time to pick up their child, things should work out well.
Blues clues pre-fab party ware and favors are quite easy to find, both online and at local department and party stores.
All bakeries are adept at Blue's Clues cakes, and blue punch is a snap, even if you choose bottled punch.
If you decide to skip the pre-made decorations, it is easy to find white plastic or paper table cloths, and paw print stamps to decorate.
Great, easy to make, take home party favors are as simple as Blue's hats.
Those $1 shops almost always have blank ball caps or sun visors for sale inexpensively, and just cutting our Blue's ears out of fabric or felt remnants from the local fabric store, a few stamped on paw prints, and using a little glue, will have your guests taking home what is, in their eyes, a treasure.
A good activity is a very simple scavenger hunt, with construction paper cut out paws with clues as to where a treasure is located.
Keep it simple, though, and help out just a bit, if you see that your help is needed.
Another suggestion would be to have a tray containing several simple things...
a whistle, a sucker, a ball, or other small items.
With guests sitting in a circle, you let them look at the tray then you take it away, and remove one item.
When you take it back, the first child to tell you which item was removed wins the item, and is "out" for the rest of the game.
This continues until everyone guesses correctly, and has a prize to take home.
Any preschooler would LOVE this Blue's Clues "Pawty!"