Use a smaller, but more user-friendly dictionary

Fewer archaic or esoteric words.
Update description
Join words with a star rather than simple concatenation

Adds minimal extra security. See: https://en.wikipedia.org/wiki/Diceware

“If words were simply concatenated rather than separated by spaces,
concatenating could form words that are already in the word list. For
example, "in" and "put" form "input"; all three words can be found in
the above mentioned word list. This could slightly decrease the
entropy, when compared with the recommended method of using spaces to
separate each word in the list.”