sorry if that came across as demanding or something, it was just meant as a suggestion.
As for tips, the best one I can offer is to use an existing skin, and duplicate the buttons on your skin in any place, layout and design, then move the buttons around on an existing skin. This is what I had to do with the skin I just created (My first as well, and I was in the same boat as you just 2 months ago). This is kinda cheating, but it is a great way to learn. At the time, when I designed my XM skin, I did not have an XM unit, and just copied button codes from another skin that did have an XM screen.
Take for example the weather page, none of the weather indicators, labels ect are in the skincommands.txt file. I just copied the BMV2 weather skin to my skin folder, and created the layout and style I wanted for my skin in Photoshop. I then changed the images refrenced in the BMV2 skin to use my images, and moved the button areas around in the skin editor to where the buttons were on my images. Then later down the road, I added dynamic buttons you can press and hold to have up to 5 cities in the weather screen, added radar & satellite images, added animated radar and satellite maps using the webplugin ect. But the starting point of the learning process started with the basic BMV2 weather skin and just continued on from there.