How to correctly throw errors in Solidity

ThrowErrorExample.sol

pragma solidity ^0.4.0;

contract ThrowErrorExample {
    
    bool isTrue = true;
    uint num = 1;
    
    //Bad code, do not emulate
    function silentFail() public view returns (uint){
        if(isTrue != true){
            return num;
        }
    }
    
    function throwsError() public view returns (uint){
        require(isTrue != true);
        return num;
    }
    
}