I bought our pink tower from Amazon, and it came with an instruction booklet which lays out how to give the pink tower lesson. That was helpful, so I gave the lesson to E(2). She really just wanted to play pretend with the pink tower, so I related the different sized blocks to the different members of the Ingalls family...the biggest was Pa, then Ma, then Mary, then Laura, and so on. This made all the difference, and she loved it! I know that probably wasn't very "Montessori" of me, but it's what she loves, and it worked for us!
After building the pink tower vertically and horizontally, I let her just play and explore with the blocks. She grabbed the instruction book and said "Let me see the designs! I want to make designs!" Unfortunately, there aren't any designs in the book, but she still loved looking at it. I'm going to make some design cards for her soon.