Preparation of figures for papers/thesis?

If it has been written somewhere, can someone point me to where there is a guide to producing figures from 2D plots?

I am using COMSOL 4.2a, and want to use some surface plots alongside legends of the colour tables used. It is bizarre that COMSOL does not provide vector graphics export. I have tried to generate a decent image using the png export (via the 'snapshot' button -- is there any other way?), but it is horrible.

How I am doing it is:
1. Use highest 'Quality' settings in each component of the plot group that has such a setting (e.g. Surface; Contour)
2. Set export resolution to 1200 DPI
3. Set image dimensions to highest possible (for me it seems 4096 pixels is the upper limit?).
4. First generate a snapshot without any includes (i.e. no title, legend, axes. etc)
5. Then generate a snapshot with the legend included.
6. In GIMP cut and paste and scale as required.

See attached file for example of trying to export a surface plot with two colour legends. The model image part of the figure is tiny, and the legends huge.

If anyone has any tips or a separate set of routines in python/matplotlib or similar already in place I would love to see it!