What are the techniques
that might displease search engines
and that I should I not use on my website?

Valuable webmaster advice and guidance is given on the main search engines which is worth noting. The following is based on this advice:-

Don't deceive your users or present different content to search engines than you display to users (commonly referred to as "cloaking")
Avoid tricks intended to improve search engine rankings. A useful test is to ask, "Does this help my users? Would I do this if search engines didn't exist?"
Don't participate in link schemes designed to increase your site's ranking or PageRank. In particular, avoid links to web spammers or "bad neighborhoods" on the web, as your own ranking may be affected adversely by those links.
Don't use unauthorised computer programs to submit pages, check rankings, etc.
Avoid hidden text (e.g. white text on a white background)
Avoid hidden links.
Don't employ cloaking or sneaky redirects
Don't load pages with irrelevant words.
Don't create multiple pages, subdomains, or domains with substantially duplicate content.
Avoid "doorway" pages (i.e. pages created just for search engines)
Avoid "cookie cutter" approaches such as affiliate programs with little or no original content.
Don't register misspellings of well-known website

Google may respond negatively to misleading practices and may reduce the ranking of an offendingw ebsite - or ban it from it's database.

If you believe that another site is abusing quality guidelines, you can report that site at

Google is using these reports to create scalable algorithms that recognize and block future spam attempts.

Find Google's advice at
http://www.google.com/webmasters/guidelines.html
Find Yahoo's advice at
http://help.yahoo.com/help/us/ysearch/basics/basics-18.html

What about some advice on good website design advice?