Hello Deanna,
I do both, patterns drawed by hand and on the computer.
to make patterns in a computer there are two kinds.
1. an image jpg (or bmp, gif, etc.)
2. a vector (cmx for me in Corel draw)
to put a only straight line in a jpg image an inch higher (without changing the rest of it) is complicated.......
the last one is a way many programs use to change lines and curves.
can you follow me here?
to go from a hand made drawing to a jpg is 'simple' by just scanning it into the computer.
then make a B/W 2 bit image.
this can be done with changing threshold black and white in the program.
to go from a jpg to a vector is done by all kind of programs, the hard part is to get the lines smooth like you had them in the drawing.
each program does this a bit different then the other, but the bottom line is the same.
a quick brain dump from me on programs used by scrollers on this forum: (random order

)
COREL

, coyote, ink scape, glimp, paint.net, post razor and more
everyone has his/hers own favorite
so it's up to you to try and see what way you like most.
hope this was helpful