You definitely want to dedicate about half of your sideboard to creatures as Modern is full of them and they come in all shapes and sizes
One of those is Sunken Ruins at $20+, with Snuff Out just above $10
For card draw, we're turning incubation into draw with Idol of Oblivion, Braids, Arisen Nightmare, and Monumental Corruption, adding poison with Infectious Inquiry, and the generic staple Syphon Mind to round things out
I got to play with Grim Backwoods, and that was cool (sac a critter, draw a card, and with Undying you don't lose the critter the first time)
They come with different abilities that either help with mana fixing or cost you something in returnlike returning a land to your owners hand, paying life, or sacrificing the land for extra mana
With the Rakdos, you may never be safe, but you will always be entertained