I have always liked to catch rainbow fish in the river just below the observatory (near castlewars) - just for something to do at times. If I am lazy I use a dueling ring to bank and then walk back to the spot. I did a lot of my early hunter levels on "tropical wagtails" and those feathers are what you need for rainbow fish.
Fishing trawler is good fun too - happy to do that whenever (my fishing is one of my lame skills - can't get into guild yet!)
If "warrior" elves want to train out at Elf Camp - fishing there is a good way to stay and train (or try for lvl 3 clue scrolls...)