I'm about to install new laminant flooring, carpeting and baseboards. My concern is a wall where the laminant and carpeting both share the same run of baseboard. How should I install the baseboards to provide the best look? If I install the baseboards on top of the laminant, which is 1/2 inch thick, then I believe that leaves to much of gap for the tack strips and the carpeting to be tucked under. Is there a best practice?

Baseboard is usually installed about 3/8 -1/2" off the sub-floor. The tack strip is in front of, not under the baseboard. The carpet pad is cut to the tack strip and the carpet is "tucked" under the baseboard. (no shoe mold w/carpet)- That said -- I think it will look best to continue the baseboard at the same height (even if you had to "tuck" some padding to fill in the difference.) You should angle-cut the shoemould to end at the laminate/carpet connection.
Good Luck--