A few creative ways to use the find shell command.
Case insensitively look for a file named your_file_name.txt
find ~/Documents -iname "YouR_FilE_NamE.txt"
Using wild cards – Case insensitively look for a file with .jpg extension
find ~/Documents -iname "*.jpg"
Easier to see when combined with less
find ~/Documents -iname "*.jpg" | less
Find Large jpg files over 5 megs
find ~/Documents -size +5M -iname "*.jpg"