Shards and crystals. My botanist is 50 and while I can make money on other items I make 90% of my gil off shards and crystals. Make sure you have all the wards (miner up to 20 as well ) just go to the level 31 nodes where 2/4 nodes give crystals. One of those nodes will give you +2 shards with each swing. Every other pass you pop a ward for 300GP at that node for +4 shards per swing, and in a hour you should have gotten hundreds of shards and crystals. Check daily which shards are in demand and going for the best prices, or save them for the weekend crafters like I do. If you want to gather items try to go for those items used in leves, and find the items used in the 3x turn ins like walnut logs. I cannot stress enough you must proactively check your boards! Market is always in flux.