For a Bob the Builder or Construction party for my 3 year old I bought the inexpensive yellow construction hardhats on the web and personalized each with a Bob the Builder type logo using each child's name (i.e. Ryan the Builder) printed out on inkjet sticker paper.  Then I also got plain canvas nail aprons that they sell at the home improvement stores for $1 each and did an iron-on of each child's personal "logo" on the center pocket and a Bob the Builder machine on each of the other two pockets using computer iron-on paper.  In the pockets I put inexpensive plastic tools that I bought in sets from EBAY with a hammer, saw, screwdriver and wrench. The kids loved their personalized builder outfits and they made great take home favors. For decoration we bought a roll of yellow "caution" tape from the home improvement store and draped it from tree to tree all over the yard, up the sidewalk and inside to the playroom. We also put some orange construction cones a friend had around in a few places with ballons coming out of the center.  Needless to say the neighbors slowed down when they passed the house to try to figure out whether we had a crime scene or not, but that gave everyone a good giggle too.  On the PC I created construction zone signs and presents went into our wheelbarrow. Our sawhorses and old doors covered in plastic sheeting made great serving tables.  We had lots of games and prizes with building blocks, construction toys in the sand box, etc. One kid favorite was our construction skills game. We gave each child a sheet of old packing foam (floral foam works too). Then the kids could have a hammer race to drive golf tee "nails" into old foam packing sheets we had using their plastic hammers. We glued metal lock washers to the tops of the tees to make "screws" that fit the plastic screwdrivers we had and they could screw those into the foam also or saw the foam with their play saws.  For snacks we decorated plain sugar cookies shaped like houses, by letting the kids "paint" on the icing on the houses using pastry brushes (cheap paint brushes washed well would work too).  Of course we also had a "Bob" cake and pinata filled with candy & tiny construction trucks.  All the take home favors fit easily into the pockets of the nail aprons.