Is there a way I can write on fondant without having the edible markers?

You can paint lettering using thinned gel/paste colourings, or use a tip to write with royal icing or buttercream. Fondant is also fab for using the letter imprints from Wilton on as a guide if your writing isn't so great, it takes the imprint really well!

I've diluted the icing colors with clear vanilla and used a very fine brush and painted it on. Just remember a little color makes it very vibrant.