It's important to leave enough time for QA testing after a project is
completed. This is possibly the first opportunity your client will
have to see the project working and moving. They may have very different
expectations and you need to time to change things if they're unhappy.
Plan for QA before it starts. Develop a simple QA testing matrix that
describes the different combinations you're testing for. Use a software
package to track the bugs, or create simple text files where people can
enter information about the bugs they encounter. Assign bugs to engineering
and production and do additional testing to make sure the bugs were actually
fixed and new bugs haven't been introduced.
Make sure your client understands what they've been given and that they
will either hire your team to maintain the site or train their in-house staff. If they're going with the in-house staff, those employees should have participated in some of the website development.
At the end of each project do a wrap-up with your team and the client to
review what worked and what didn't. Now is the time to change your process
and update documentation before the next one begins. This is also the most
psychologically damaging part of the process for a project manager because
it's everyone's chance to tell you what they disliked about the process. But
that's just the way it is.
Above all, have a party. You all worked hard and tried your best, so
you might as well celebrate a little!