Web sites come in all shapes and sizes. Therefore, it's important to appropriately manage the development process as you progress.
For example, changes to a small blog can be made in the live environment, but the same does not hold true for a more mission critical system. As your site becomes more important (and more complex) you'll need to exercise additional care to insure unexpected mistakes are not made. Usually this means working in a duplicate environment which can be kept private in order to test proposed changes.
Review the following description to see how this can be accomplished (using WordPress as an example). Of course there are many ways to implement such a process and so you might consider an overview of the concept itself.
Naturally, there are basic and straightforward tools one can use too. Automated tests (such as this one) can be used as a basic review of your site design. Just remember, nothing can replace experienced human judgment. Bear in mind this kind of test exercises the site and its design... not necessarily the server itself. In other words any heavy, unoptimized, or poorly designed site is likely to be slow no matter how fast the server. It's important that one doesn't jump to conclusions ;-)
Given that there are a lot of powerful and easy to use web-site software packages (e.g. Wordpress, Zikula, Drupal, PrestaShop, etc), make sure not to inadvertently overload your site. Liberal use of plug-ins and unoptimized graphic images often slow things down. When this happens, distinguishing what is an acceptable design trade-off and what was just an experiment gone wrong can be tricky. A few suggestions follow:
Just because the automated test complains, that doesn't mean you've made a mistake. Very often these tests will complain about things like "too many redirects" but a redirect is a powerful technique which can guide your users to the right location. Such a benefit may easily outweigh any slight delay incurred when loading your site. In this case, you may simply ignore the issue or test the landing URL instead of the URL that's intentionally designed to redirect.
Finally remember, if you're stuck or just don't have the time... we offer extended support contracts to our hosting customers. Not only are we great hosts, but our consulting and contracting services are second to none!
Please don't hesitate to contact us when dealing with tough problems; we're happy to help.