This decoupage project was simpler and therefore, much more successful than the last one at keeping my four year old interested. Since the advent of GPS, paper maps have become somewhat obsolete. I picked up a whole bunch of second-hand local maps for only a dollar and this is the first project I have tried with them.
Things you will need:

Second-hand map of local area – Te Upoko o te Ika a Māui Wellington Region
MDF letters from craft store
Mod podge – decoupage sealer, glue and finish – I got the kids washable kind
Mod podge clear acrylic sealer
Black washable paint
Scissors
Paint brush
Craft knife
Instructions:

Take the MDF letters and paint the edges with black paint. Leave to dry. Doing this with a four year old we used washable paint. Remember to give the letters a spray with the acrylic sealer before getting them wet again with mod podge.
Take areas of the map that you want on your letters and cut them out with scissors, leaving a bit of a margin. I made sure our home address was one of the areas I used.
Apply mod podge to the back of the map and stick on the letters. Make sure you put the letters in the right orientation for the map. We almost ended up with an upside-down E. In hindsight, I would have left the maps to dry before cutting around the letters with a craft knife. This would have left sharper edges. However, I had an impatient (she inherited that from me) four year old with me, so we forged ahead. I had her cut around the letters with scissors, and “finished them off” myself with a craft knife for safety reasons.
Apply a couple of layers of mod podge over the top of the maps, and down the side of the letters until happy with the result. Don’t forget to spray on a final layer of acrylic sealer to make sure the letters are not tacky to the touch.

What the kids can do:
Painting the letters: Easily done with a paint brush. My four year old wanted to paint the front of the letters as well, not necessary, but we did it anyway. You may want to touch up any spots that were missed.
Cutting out the map: This will depend on the child’s scissor skills. My four year hold had a go at this. There is no need to cut exactly to size, as long as things are not cut too small it will be just fine.
Gluing the map: Easily done with a paint brush. I had to do the second coat of mod podge alone, but otherwise miss four was interested in participating in this project.
Cutting out the letters: I had my four year old cut around the glued on map with scissors, and I “finished it off” with a craft knife. She felt like she was doing something and avoided any craft knife associated injuries.