There are several different ways to get wow classic gold in the auction house. Each of them needs a different game style and level of understanding. It is important to choose those that match your strengths and preferences in order to achieve outstanding results.
The farm is the easiest and surest way to make gold. It involves using mining (herbs, skinning, fishing) to collect trade goods and then sell them on the auction house. Usually, this will not give you a lot of gold per hour, but the risks involved are small and the level of knowledge required to start is small.
Craft refers to using your production specialty (Jewel processing, instruction, alchemy, etc.) to make items and sell them on the auction house. It requires that the selected professional level be improved and the valuable recipe is stored, and know which products are popular. Craft has great potential, but it involves investment and risk.
The most advanced way to make gold. It includes any form of purchase and resale of goods. It has the greatest potential to earn a lot of gold per hour, but often requires a good understanding of the world of war, especially the market in your area.