There are various ways where you can gain/ earn more bitcoins.
By Mining
You can earn Bitcoin by mining them, but first the mining rewards have reduced significantly. But mining is a long process beacause the cost of setting up a Bitcion mining farm is too much, you need to invest in crores to set up hardware machines which can mine bitcoin.
By Joining Exchange Referral Program
Almost everyone is using exchanges to do various trades, therefore by referring your friends to trade using you referral account is one of the easiest ways to earn FREE Bitcoin.
Check Referral Program
Give $5, Get $5
Refer your friends and earn $5 when they complete a transaction for a minimum of $100. And guess what?? Your friend earns $5 too. Isn’t that awesome!!