In order to set default values for variables, I find the start of my functions littered with

if nargin < 1 || isempty(x)
x = 1;
end

if nargin < 2 || isempty(y)
y = 3;
end
etc.

This is pretty ugly, so I've created a wrapper to prettify it. Honestly, it's so simple that I nearly didn't upload this, but it does make your functions cleaner. Now the above is transformed to

SetDefaultValue(1, 'x', 1);
SetDefaultValue(2, 'y', 3);

Note that there are other ways to set defaults. See
http://blogs.mathworks.com/loren/2009/05/05/nice-way-to-set-function-defaults/