I've used slime tubes quite successfully (but they are not for weight weenies). I am particularly impressed with them on my kiddy trailer - it had less chunky tyres than the bike and being wider than the bike is often scraping through the thorny rubbish at the side of the trail. Prior to going slime it was picking up atleast one puncture on almost every trip out. Since going slime its had none.
I've also put them in my bike tyres and lasted well over a year without a puncture (I'd guess that is saving a couple of punctures) - but it might depend what causes the puncture - if it is pinch flats then slime may not cope with that - if its thorns you'll probably be fine.
There are a couple of downsides to slime that might not be too well publicised. (1) if you do get a puncture that slime can't self seal then getting that bit of tube clean enough to use a patch is difficult - probably possible in the garage, but not fun whilst being eaten by midges (2) getting the old tube out can be rather tricky (I think there may be a "right" way to do this [possibly put valve at top to let slime gather at the bottom? but I didn't do this recently and the slime sealed inside the valve - meaning I had to cut the valve off. Because they work so well you may be out of practice changing tubes and forget this bit of the instructions!]
I'd say there are two obvious things to reducing your puncture frequency: (1) run your tyres at higher pressure (2) make sure your tubes are the right size for your tyres [on a recent trip the only person who got punctures was running 1.75-2.1" tubes in 2.2" tyres - they stopped the following day when running larger tubes].
I think some tyres are more puncture resistant than others but none are puncture proof.