You're right about those giveaways. They may work for some people, but they also eat into your potential profits, which--if you're self-publishing--tend to be slim to nonexistent even if you don't do them.

The same goes for anything else you do to promote your book that costs money, such as creating custom bookmarks or other items with the name of your book on them.

You need to do a very clear-eyed cost/benefit analysis of such things if you don't want to lose money on a book.