Please forgive me if I'm not original but this is my personal experience.
After 2 years, I have 3 level 70s alliance side. I was a PVEer and only did PVP in BGs on occasion. Recently I got bored with PVE as I usually do shortly after hitting 70. This time a made a twink and went into WSG at 19. Even still, i lost most matches to the Horde so I decided to re-roll Horde on a PVP realm.
This means I have no access to my resources. I needed to start from nothing.
I initially made a mistake but it turns out to have worked in my favor but I'll get to that. I was able to do this over the course of 2 separate weekends.
Weekend 1:
I rolled a BELF Lock to level 10 and trained Tailor and Enchanting (I guess 5 would be fine for this purpose.) Then parked her at the AH/Bank.
Next, I rolled an Orc Hunter and leveled to 18. This was my mistake. I have since decided that Hunters are great in World PVP, BGs and leveling but may not be the best choice for me in endgame PVP (Arena)
Weekend 2:
Rolled UD Rogue. This will be my Twink. Leveled to 10 normally but then moved to Orgrimmar and will finish in the Orc/Troll zone. By Sunday, I was level 15. I stopped leveling and moved to focus on Cooking, 1st aid, Fishing, Mining and Engineering. I ran around Durotar and Barrens mining everything and got into the 70s. I took the hunter and dropped LW and picked up mining as well. I don't want to really do much more soloing on the rogue now as I want to reserver the next few levels for running my instances to get my Blue gear. But I did level fishing to 150 and collected 4 stacks of Deviate fish. I need fishing for both money and to go to STV and get the fishing hat with 15 Stam that Twinks love. Sent the deviates and the ore to the lock as well as any other drops.
I am now using my level 18 Hunter to gather ore. Even just copper alone between Durotar and the Barrens, has yielded a significant profit.
I now have a level 15 Rogue with over 100 Gold and it's growing fast.
This whole Process has only taken me a few hours extra outside of the normal leveling grind.
I have joined a guild, They have low level alts so I will get runs through SFk and WC.
There is NO reason why anyone cannot have a Twinked out Character by level 19!
It took 2 weekends of playing time for me.
I hope this is useful.