For designing glyphs (character patterns) start with some squared paper and a pencil and design one that has the right dimensions...
Then treat the squares as bit positions in a binary number, treating each row separately - this gives a value to shift into the LED drivers (best expressed in hexadecimal). Send the correct rows of data to the correct rows of LEDs and the pattern should appear lit up. However you have to be quite clear as to what counts as a row as opposed to column and the directions up/down/left/right. At least mistakes will be quite easy to see.