How? early 1970s with my Pop and his brothers. Camping, panning and sluicing up around Slaty Creek near Creswick. No detectors then. Did lots of specking for gold on the ground after rain. Learnt to pan with small shot gun pellets. Pan off and still have 10 - commence panning for real. Great bushmen, tough, funny blokes. I developed a love for gold, history, wild-life and native flora. (and a dash of Melbourne Bitter in vegamite glasses with Tarax lemonade)
By a process of years and years, early VLF detectors right up until now with PIs. Over the years have had some great mentors, Timmy Raven (old timber worker - could read the ground like no other), Jim Stewart (best prospector I have ever met) and Tony Mills (very cluey bloke) to name a few.
Best advice? Learn to read the ground, learn to look for indicators, never ever walk backwards, be patient and the best bit..... treat the bush like **** - it will get you back a hundred fold.