Tips for optimizing prints done at pro lab

At present I don't have the room or inclination to do my own printing. I was wondering if there are any tips for newbies when taking their files to a pro lab for printing. For instance, how can I make sure the print comes out the same as the image on my PC screen?

I send my images made with my dslr out to a service to have them printed with a lightjet onto Kodak Endura paper. To get them correct, talk to the lab about what bit depth and colorspace they need to be in. In my case, I calibrated my monitor first and foremost, then set the colorspace as sRGB and 8 bit. I just recently did a custom print profile from their machine, but I haven't made comparison prints to check it. The colors using sRGB have been very good, I just am curious if I can get them better.