One thing you can do is to make use of passphrases - concatenation of words. Insert a number and special symbol at the end or somewhere in the phrase.
I get the words in the following manner: There are 615 pages in my Merriam-Webster dictionary. For each word, multiply 615 times a number from the RAND function of a calculator. (Even an iPhone calculator has that function.) Go to the page number that results from that calculation and then choose a word. You can use the RAND function again to choose a word from the page; but, I merely choose one I like. Add an underscore plus one or two digits from another RAND press.