When researching in newspapers, "back search" news clippings. When you find an obituary or news clipping mounted on an index or note card in your relatives papers with no date or newspaper name, take a phrase from the text and enter it into Google or another search engine. You may find that it has been digitized and that will help you find it and perhaps give you more information.
If you're still looking for that elusive ancestor, try revisiting the census for overlooked information. Or if you didn't find that ancestor the first time, perhaps the enumeration misheard the ancestor or the person giving the information. Look for the person using all those clues we've talked about. Use only the first initial, look for the parents, look using only the surname, etc. Don't forget that perhaps they lied, or the age may be way off, or the gender might be wro