The easiest way is to add it when you plot
plot(x,y,'style')
where 'style' is a combination of color, marker and linestyle, in that order. For example
plot(x,y,'rs--')
gives you a dashed red line with square markers. A list of marker and linetypes can be found in the doc . By default you get a marker on each data-point. You can however reduce the frequency of markers by specifying a vector with 'MarkerIndices' if you have a new version of MATLAB.
It is proper to always output a handle when you plot something.
h = plot(x,y)
By doing so, you can easily change the lineproperties of that plot after plotting, for example:
set(h,'linestyle','--','color','r','marker','s')
You can set the property for multiple line objects on a single line, by passing all your handles into the set function.
If you fancy some specific set of marker/linestyles, then you could also learn about the 'LineStyleOrder' argument of the axes. You can basically configure the axes to use a certain set of marker/linestyles, just like the default is to use a certain set of colors.
