How do I make money efficiently?

I've found the best way to make money is pick up ingredients in the wild, make potions and sell them.

Easy to find

Wild ingredients are easy to find. Or you can buy ingredients from many vendors. Avoid buying expensive ingredients like void salts, fire salts, daedra hearts etc. The return isn't worth the cost.

They're light

Most ingredients weigh little. If you make a lot of potions and can't sell them all, the potions also don't weigh a lot - 100 potions weigh about the same as 1 piece of heavy armor. Their value/weight ratio is high.

They sell for a lot

I regularly sell a 0.1 weight potion for $200. There are other items with higher value/weight ratios, but I can quickly make 10 of these with ingredients that aren't hard to find. This works best for invisibility, because you can sell it for squillions. I've made around 20k mostly from potions.

I have seen potions with values in the thousands!

It's good for your alchemy skill

It'll also help your alchemy skill, and as your alchemy skill gets higher, you'll make more valuable potions.

You'll always have potions

There's nothing worse than getting into a battle without the right potions. Having a few spare potions for health and magika on hand will help you a lot!

Win win win!

Method 1: Transmute spell + iron ore + smithing = profit.

Find the Transmute spell (at the Halted Stream Camp north of Whiterun or at the Ansilvund Burial Chambers, northeast of Shor's Stone). I've found it there on 2 characters, so I assume it is static (found on a table/desk, not chest).

Steps to success:

• Go get tons of iron ore. Easy from several dungeons/mines/etc.
• Cast transmute, it will create a piece of silver ore.
• Drop silver ore if you have a lot of lower quality gems(likely from mining all that iron), as you can make silver jewelry that will sell for more than standard gold jewelry.
• Cast transmute again, rinse repeat until you have enough silver ore to make all the 'gem' silver jewelry with smithing.
• After that, cast transmute all day and night to create gold ore. Do not drop silver ore, as it will all get converted to gold.
• Go to a furnace (ex: Whiterun blacksmith), and turn your ore into bars.
• Go to Forge and create all the jewelry.
• Move to the 'final' method below.

Note: This is an Alteration spell, so consider wearing some items with Alteration bonuses and mana regen to help counter the cost.

Method 2: Make iron daggers

• Buy iron ore/bars from anywhere you can, also go mine it if you are a real cheapskate. (the ore is ~5g), also get plenty of leather strips by either buying or tanning.
• Create iron daggers at an anvil (1 iron bar, 1 leather strip).
• Rinse, repeat until you have as many daggers as you do filled petty/common soul gems.
• Move on to the final 'method' below.

Both Methods finale: Enchant the jewelry/daggers with an expensive enchant. Daggers are the better choice.

• Get a bunch of Petty (common is better for weapons) soul gems. Buy them from merchants, as each item will sell for over 900g even with low speechcraft. So a 300g soul gem is still a huge profit.
• This works by either getting the conjuration perk to add soul trap to bound weapons (and using the bound bow imo), or adding a short duration soul trap to a weapon.
• Then just use an altar to enchant each jewelry/dagger piece with you most valuable known enchantment using the filled soul gems. I highly recommend the BANISH enchant(I first found it around level 25, it is the one that banishes summoned Daedra back to oblivion), as it makes nearly anything worth over 1000g, even mining picks.
• Now run around and sell your items! Most vendors will only have enough for 1 dagger at a time. So I use this as a way to clean out vendors of ore/items I may want. But out their inventory, sell 3 daggers and still make a profit.

Get a spouse! They open a store to keep them busy... you can ask once a day how their store is doing and they hand you 100g. This accumulates, so if you ask 5 days later, they give you 500g. I stay at home and sleep 24 hours 10 times - hubby gives me 1000g. It only takes a little over 4 minutes for every 1000g.