I had all but given up on Silver printing and was concentrating on Platinum/Palladium and Cyanotype. I was never really satisfied in the results I was getting from my silver prints. "Why did everyone elses turn out better than mine?" That was what I was always asking myself. However, I took a 2 day one on one printing workshop from Per Volquartz here in California and it really opened my eyes to silver printing. Seeing how a master printer approaches his printing is an terrific learning experience. I suggest that there isn't anything wrong with your contact printing process (I too work in 8 x 10 and 8 x 20), the problem is that you might need to learn more about printing.
What I learned from Per is that just about all of my images needed some dodging/burning and sometimes some bleaching to give them that "real look" that I wanted. With PT/PD and Cyanotype, I wasn't really needing to dodge and burn much because the process and materials was completely different from silver.
Now I'm back to silver printing and loving it. I'm taking the lessons I learned from Per and using them in my contact printing, and my contact prints are much better. You should think of contact prints as more than just a quick shot at getting something that you can see what is in the negative. Try to make your contact prints with the same thinking as making final prints - that you really want them to look good.
Now, California is obviously way to far away from Brisbane to consider working with Per, and the upcoming 2 weeks is not enough time to get into a workshop. However, I would still suggest that you check around your area and see if any "expert" printers either teach workshops or would consider working with you one on one in the darkroom.
Assuming that you use variable contrast paper, I would also work at learning what the different filters can do for you. Do some research on split filter printing with two filters (one for shadows and one for highlights). Working with the different contrast filters has also helped me a lot in getting better prints.
Hope this helps and good luck.