I prepare mayonnaise in a very simple way.
Once you have a basic mayonnaise you can add vegetables and get what in Italy we call Russian salad, in Russia it's called Salad Olivier and in Germany it's known as Italian salad. I don't know which one applies for US and Canada.
If you add some ketchup you get a pink sauce which is good with shrimps.
I dont' pay too much attention at quantities as I trust my eyes but these should do.

Ingredients:
2 egg yolks
1 glass olive oil (a good quality please)
2 spooful (more or less) lemon juice or vinegar or 1 and 1
salt
Egg yolks and oil must be at room temperature.

Put the two yolks in a bowl, beat them vigorously with an electric whisker, add oil very slowly. When it starts to thicken add some lemon juice, beat again, add oil and lemon juice and beat to the desired thickness. Add salt. It might taste too strong if you are used to commercial products.

If you prefer a quicker way to prepare it, have a look at this

mayonnaise

Ada