Three quarters through mine at the moment and have done a couple of longer navs. One from Melbourne to Adelaide! Did plenty of approaches on the way there and back. Had to divert due to storms over Adelaide all in all a really good learning exercise. Going to do a few shorter exercises in the next week and maybe a long nav up north to finish it off before a pre test.
I would suggest finding an instructor that will take you into imc and make you hand fly it for the most part. AP is good on long sectors. But if you get the chance to get into IMC make sure you hand fly it!
Not sure how sophisticated your aircraft is but also be very familiar with all the wizardry (glass) prior. would be good for you to be shown the steam version and glass version of instrument flying. Quite different!