A template I use to create memos and recommendations. The result looks like this. The signature is from the John von Neumann Wikipedia article and is public domain.
Clone the repository.
git clone https://github.com/bmccary/utd-math-memo.git
The directory utd-math-memo will be created. Possibly move it to a new name, but anyhow change to that directory.
mv utd-math-memo recommendation-letter-for-einstein-albert
cd recommendation-letter-for-einstein-albert
Edit memo.tex and then
make
You'll want to replace the signature.png file with your own.