There are a few 'likely' areas, however, as I've found recently, as these cars are all around 20 years old, the leak could really be anywhere. The only thing is a failed head gasket is pretty much the last place on the list - some cars it's the first, so pat yourself on the back for choosing a better car
This list is
sort of in likelihood order...
sort of. Happy to be disagreed with!
Ok, so the oil cooler plate is a common one, these corrode, however as they're at the very middle of the engine, the coolant evaporates/boils away before you ever get to see any 'drips' anywhere
HBV, this is at the back of the engine, looks like a black starship enterprise, known for failing.
Hoses - quite obvious, but worth looking at the easy to access ones. Just see if you can feel any wet at the joins - some are fairly inaccessible, check the easy ones first!
Water pump, these can leak (Not as bad a job as it sounds, actually, should/could have been replaced at last timing kit change.
Thermostat o ring/coolant transfer pipe. (worse job than it sounds, still doable for the DIYer, but a lot more of pain to get to than many cars)
Coolant bridge ('joins' the two banks) these can corrode where hoses meet. Necessary to remove this if you are looking at replacing the oil cooler plate, so worth cleaning up as preventative maintenance anyway.
but first port of call may well be... the cap. Yellow header tank cap are often found to have leaky seals, and a tenner could be a cheap fix.
If you want to strip things down there's a 'cold pressure test' than can be done with very simple tools to 100% check for leaks everywhere..