Keep headers/logos under 125 pixels high. It takes up valuable viewing space, especially for laptop users, that is best left for the good stuff to appear"above the fold." Take a cue from the big companies, simple logos done well say it all. This is our #1 pet peeve - screaming logos and headers!
WordPress cloning, as it applies to rename your login url to secure your wordpress website, is the act of creating an exact replica of your WordPress install. What is good is that in only a few clicks, you can do it with the right software. There are a number of reasons why you may want to do this. Here are only a few.
There are ways to pull off this, and many of them involve re-establishing databases and more and FTPing files, exporting and copying. Some of these are very complex, so it is important that you select the one that is right. Then you might want to look into using a plugin for WordPress backups, if you are not of the technical persuasion.
Yes, you want to do regular backups of your website. I recommend at least a weekly database backup and a monthly "full" backup. More. Definitely more if you make changes and regular additions to your website. If you make changes multiple times a day, or have a community of people that are in there all the time, a daily backup should be a minimum.
Another step to take to make WordPress secure is to always upgrade WordPress to the latest version. The main reason for this is that with each upgrade there More Help come fixes for old security holes which makes it essential to upgrade early.
Free software: If you have installed scripts that are free search Google for'wordpress security'. You will get many tips.