This is something my husband and I are also looking into. I've done a few google searches on ideas, and here's a few that I liked:
Customized Pet Products: embroidery on beds, blankets, and clothing; painted crates; hand made or all natural treats and toys.
Customized or Air Brush T shirts
Custom Wood Carving
Customized / Individually Tailored Clothing
Customized Holiday or Seasonal Gifts: Easter baskets, valentines gifts, Christmas ornaments, etc
Custom Banners and Flags
I'm sure there's more, but I'm not sure how profitable any of it is. My advice, if there's 2 working, get into 2 different markets that have low start ups and try to divide and conquer