I was wondering what is the best practice for creating forms in Wordpress? As a developer I hesitate to use a plugin like CForms, but I can understand why someone would like to use it. In the end I want to know the following:
What do you mean by "in Wordpress"? Do you just mean placing the form HTML in a Wordpress template? Or storing data collected in the Wordpress DB? If you just want to create a form on your site, there's nothing Wordpress-specific to worry about. I believe there's some special Wordpress data facilities you can use if you're creating a widget or plugin or whatever they're called now. But if you're not, just create the HTML, and point it at a target URL that processes the values and puts them in a DB, Wordpress or otherwise. That target URL could be a separate PHP resource, or the same page. If it's the same page, you just need to include your PHP somewhere in the main Wordpress flow.
I don't use any part of the WordPress API for forms. You could automatically grab the name and e-mail address out of the cookie WordPress creates when someone leaves a comment, if you want to try to auto-populate some fields.
An easy way to handle forms is to use Page Templates. That lets you create a new PHP file for a specific page, overriding the default page template of the theme. Then you can simply have the form post to itself and this one page template handles the processing as well.
A lot of what's available for WordPress in the way of addins, and what gets a lot of attention, is stuff that I find makes little use if you have programming and general web skills. Almost always they seem to (necessarily) overgeneralize a requirement with a zillion options and configuration requirements because they are first of all designed for non- or barely-programmers.
Just learn the fundamental paradigms, scratch your head and wonder why nothing is consistently abstracted and/or encapsulated, get over it, and use what you already know about php and HTML-based forms. WordPress doesn't add much in the way of either tools or constraints.
I find the Widget feature applies usefully to most everything these days, and Forms is a candidate. But that's my own WordPress viewing prism - YMMV.