Pick something you're extremely passionate about.
Make 4-5 Instagram accounts related around your niche with related names.
If I'm passionate about gardening, or travel, or fashion. I'll make accounts related one.
For example, gardening, one name could be:
gardeningthingsdaily
On the account, you'd obviously fill in the bio with something like:
"Gardening posts daily
Tools, techniques, and tricks found here
Follow if you're interested in gardening."
A profile picture of course.
Repeat for 3-4 more accounts, with different names, but related to gardening, filled in bios, and profile pictures.
This is where some will power comes in.
Everyday on each account post 1-2 pictures, with related hashtags. And everyday on each account, find a profile related to your niche, and make sure it's active. On it's most recent posts, start following the people who liked it, start slow and follow about 30 a day, each day increase by about 10 until you start hitting 100 a day. You can probably do more, but it's what I've been doing. This is to ensure Instagram doesn't ban you. Starts unfollowing when you hit 500 following, by unfollowing 50 a day.
THIS CAN BE AUTOMATED. You have money to invest, I'd suggest a bot, read into that more by doing research.
This will build you multiple Instagram accounts with followers of about 5k+.
4 accounts with 5k followers = 25k reach.
From here you can start looking at ways of monetization. An example could be an affiliate website with gardening tools, articles, and reviews, with affiliate links to amazon products (yours of course). Continue to be active on ALL accounts and keep building them, you'll see your hard work pay off.
I g2g now, i'll see if I can post more later for you, good luck.