Actually structure traders are a cinch to level.
Stay on the starter station and buy mats from the resource trader (standing right next to the trader npc). He will sell you sets of 40 metal for 100cr. Level up to about 7 or so and do every quest on the tutorial station and make some credits. After your done doing that and BEFORE you leave the station hit the trader again until you level. Personally I made solar survey devices till I hit 10.
Now it does get slightly tricky from here on because of extractors. You will recieve one mineral extractor from the trader on the station and some energy to power it. You will need Wind generators to gather energy to power your extractors.
There are a good amount of guides for placing extractors on swgcraft.com.
For leveling though you will need these extractors and enough energy to power them
4x Personal Mineral Extractors - targeted on Low grade (type doesn't matter)
3x Personal Mineral Extractors - targeted on metal (place on for each steel, aluminum, and copper)
3x Personal Moisture Vaporators - targeted on a good supply of water.
10-18: make extractors on practice mode
18-42: make Crafting stations (450 metal per run)(don't worry about the optional parts)
42-86: make Fountains (this is the longest part, 1000 LG ore, 500 water, 300 metal)
86-90: make gungan statues (when you get close enough to 86 change the 3 mineral extractors over to gemstones you will need ALOT of them)(2000 LG ore, 1000 Gemstone)
granted bigger extractors will help you recover material much faster, and it is well worth investing in them. Additionally I had a combat toon bringing in the money for my trader to keep the maintenance paid on all my extractors, as well as getting my entertainer buffs.
Once 90 you can change your profession to:
Engineer
Domestics
Munitions
and you will NOT lose your levels for doing the change.