Thinking back through the galleries I tried to use in the past and with a bit of help from a friend:-
I have a stepped plan for making the most of the headway advanced gallery leaf. The core steps remain exactly the same as the Headway tutorial video – these tips just expand on the tutorial.
1. Pre-determine your image size or ratio. I like 16:10 (1/1.6 or 0.625) as it is more or less the new monitor standard so images can be used as screen savers.[1680 x 1050 / 1920 x 1200 / 2560 x 1600 all share this ratio]
2. Choose the maximum width for the gallery pages (1200 px)
3. Set your image thumbnails to the same ratio. My thumbnails will be set to 160 x 100.
4. Checking with firebug / element inspector I found that Headway resizes images to 986 x 705 if you use the resize to fit check box.
5. Resize all your images to less than the figures in 4. I have chosen 975 x 609 – to keep to my prefered ratio of 16:10. Headway will accept PNG-24 images (for those reducing from DNG format) – I recommend you resize at maximum quality for JPEG.
6. Upload your images to their respective galleries.
7. In the Visual Editor open the Gallery Options pop-up and follow steps 8. & 9.
8. Uncheck the Crop Images box.
9. Check the Image Resizing box.