I can usually make at least 3 accounts per IP if you use a different browser for each account.
Most home internet connections get their IP from a DHCP server. So, if you know how to force the DHCP server to give a new IP then making accounts becomes fairly trivial. Some ISPs may allow you to do a DHCP flush to get a new address, most won't. Getting a new IP from the DHCP server can be achieved by attaching a different device to your modem, or what the DHCP server thinks is a different device. Trick the DHCP server into thinking you've attached a new device by changing the MAC address of the device. These days decent home routers will let you change your mac (mine is a netgear as this in advanced settings). Otherwise you can connect directly to the modem and use one of the many tools for any OS to change your MAC.
With this method I can make as many accounts as I need, but I don't need many accounts.
Things I am un-sure of on this method and would be helpful if anyone else knows:
1. Can you make more than 3 accounts per IP if you try even more browsers/user agents. I have not tested that enough to know for sure.
2. What happens when you exhaust the DHCP ip space. Like if you end up getting the same IP after a while would you be able to make accounts again? In other words, how long does the verification last on an IP?
As a final note, I'd also like to point out you can buy phone verified accounts pretty cheep here on BHW. Depending on your needs I'd definitely recommend going that route.