The easiest way, IMHO, is editing your hosts file (your computer, not at the server).
If you use MacOS: sudo vim /private/etc/hosts
Linux: sudo vim /etc/hosts
Windows: Open c:\windows\system32\drivers\etc\hosts
Add one line to this file:
1.2.3.4 example.com www.example.com
Save the file and access your site. You'll bypass any DNS resolution and access your site before actually publishing it.