I haven't used a bot yet ... to afraid to get caught because I forgot NOT to leave it on over night lol. I would probably do something stupid like go watch TV for a couple hours and fall asleep ... wake up with a banned account ><
whm's have the easiest way to make gil -- tele-taxi, as a few others already pointed out

It's not a huge flow of gil but it is pretty steady income. Yes, you could go camp a NM and possible get a drop worth millions but a few people here said they were 0/8 and such. For a NM that spawns once every 3 hrs or more that would suck.
What they did with lizzy was a good idea ... too many people were killing everything in the area and leaving nothing for lowlvls to exp on. You can probably expect some of the other highly camped easy NM's to follow soon
You can always take up mining or one of the other farmings like that. You can make a pretty good profit at low levels mining in bastok. Don't plan on getting a bunch of darksteel just go for the over all gil. Bring a few stacks of fire crystals with you and turn the ore into things that stack so they don't take up a lot of space ^^ you will make more money this way too. 5 stacks of picks use get me about 100k profit by the time everything sold; if a darksteel or something else of value dropped, I got more. Don't loose faith here if you loose money sometimes because ... it can happen. I make gil much more often than I loose it though.
Now I mine in Newton Movolopolis ... yes even a 75 can get aggro but its not mined that much on my server. Same with ifrit culdron and old movolpolis ... I think you can mine there with no aggro around 55-57? don' t remember off hand. As long as you stay to the mining trails you shouldn't find aggro.
Getting gil takes time ... but its worth it in the end. ^^v good luck ^^v