Use the e function instead of ones or zeros
Octave has an e function, which I don't think is very well known. It's like onesor zeros, but it produces copies of the number e. And it's shorter. This function can be useful sometimes:
Instead of ones(m,n) you can use ~~e(m,n) if you can get away with having true instead of 1. Or even use e(m,n) directly if all ...
Abuse == short circuiting
If you have:
A function with a side effect (such as print);
That you only want to run if some condition is (or is not) met.
Then you might be able to use == over or to save a byte.
Here's printing all numbers n under 100 that have f(n) less than 2:
for n in range(100):f(n)<2and print(n)
# Invert condition
for n in ...