I'll try to answer this even though I'm pretty inefficient with money/gold.
Dungeons are still an okay source of income, but only if you get into a really good speed-clearing group. I would personally rather do fractals, specifically T4 dailies. You'll end up getting a decent amount of gold just from the boxes and potentially a little more if you sell your agony infusions/matrices. Also good for getting ascended gear that you would otherwise have to spend gold crafting. They are also just fun imo.
I also get a decent amount of gold just refining and selling mid-tier common materials, like seasoned planks and iron ingots. You'll get some of these materials naturally from salvage items in the new ls3 maps (leather mostly) and others from opening most gear and champ bags on lower level characters.
see
http://silverwastes.loltools.net/index.html
or
https://www.reddit.com/r/Guildwars2/comments/3yz2bf/making_the_most_out_of_bags_of_gear/
Every couple months I dump out my mid-tier materials for decent gold. Some people will prefer to go a step further and refine into the T7 mats but for my personal preference I don't like having the daily timegate on a component of that and I prefer the sale velocity of the refined materials as is, or maybe I'm just lazy.
Silverwastes is the most common thing people use to get champ bags quickly, using a RIBA rotation (Red fort, Indigo, Blue, Amber), but it will potentially test your sanity, just a heads up.
Some people will park alternate characters at rich nodes or at map chests with a chance of stuff like silver doubloons...I've never gotten into parking people anywhere (except the T5 wood farm in Malchors). You can make decent money I bet gathering from mid-level map trees and ore nodes, but it's never been something I care to do so idk much about that.
Another thing I do for money is that I visit the
https://wiki.guildwars2.com/wiki/Pact_Supply_Network_Agent and grab the Mapping Material item which I then use on
either week 2 or 5. Obviously, it's a daily chore that is a long game, but it's nice to get a stack+ of T6 blood for "free" every other month.
Always salvage rare items with a mystic kit or equivalent. Even if you're not selling the ectos, you're not buying them.
Lastly from what I can think of is conversion of other wallet currencies.
gw2efficiency is your friend here. It basically tells you which dungeon gear you should salvage if you want to dump tokens etc. Some of these are simple, like converting badges of honor into badges of tribute to sell, others involve mystic forge promotion or such, which I personally kinda loathe because I hate repeated use of the forge, but I guess it depends on the person. Laurels into heavy crafting bags (sell the t6 mats) is another easy one.
Btw, never do instant sell on stuff going to the Trading Post. List it, undercut if you have to. It will sell eventually and it's basically giving up free gold to not do that.