Lots of factors go into this... Niche, engagement etc..
Shoutouts are likely your best earner with a 1m following.. but never DM directly from your main account, create a fanpage for your main account built it up to 5k-10k and use this to contact potential clients. Have an email in your bio also. At 1m tho chances are people are already going to be DMing you requesting shoutouts.
Affiliate marketing is also a viable option but will be very dependable on your niche and it's pivotal that your product is quality otherwise you will lose your creditability.