1. Anchor Text or Title? this is most valuable part of the incoming link in respect to search engines and regular visitors. The anchor text must contain keywords or key phrases but at the same time it should not be stuffed with them. You can always mix secondary key phrases with the primary one.

For example, if my primary key phrase is directory submission services and related secondary key phrases are Manual Directory Submission and submit website, I would like to write the anchor text as

a) Manual Directory Submission Services ? Submit your website to niche directories (if such a long sentence is supported).

b) Manual website submission to niche directories.

2. Description- The description part of a link is also important both from visitor's and search engine's point of view. If you go through some link directories, you will find that the description parts are no better then a sales speech. Good directories will not allow promotional descriptions. A good description should try to explain the anchor text or should focus on the objective in a state of the art manner.

At present, major search engines like Google are looking for related content near the link. It is not enough to have keywords in the anchor text alone; the description part should have secondary key phrases and related words in it. However, if you have other options, do not go for lonely links. And always remember that anchor text is as good as its surrounding text.

3. Number of links in that page ? How many links does that page have? If the number of links in that page is more than 10, you should not expect much help. But as we always say, every little bit counts in SEO.

4. Proper category ? Find out if that directory has proper category and subcategory to submit your site. Some directories may allow you to suggest a suitable category; otherwise you may leave that one.

5. Quality of other links ? Before submitting your link to any directory, guess the possible page from where you may get a link. Now, look for other out going links from that page. If other outgoing links point to some great sites, you should select that page for submission irrespective of the number.

6. Directory submission per day ? Do not submit to more then 20 directories per day from the same IP address.

7. Manual submission ? Do not go for automated submission ? it is always safe to manually submit your site in the best directories.

8. Cached pages ? Look if the sub pages (and sub category pages) are cached by search engines or not.

9. Supplementary Index ? Do a Google site search to find out if some pages of that directory are in the supplemental index or not.

10. Blank pages ? Find out if some sub category or category pages are empty or not. Directories with ?Under construction? or ?Empty pages? are not good for your site's health.

11. Meta Attributes - Look for ?noindex? or ?nofollow? attributes in Meta Description along with Java Script links ? they do not pass PR juice.

These are some of the primary conditions that you should follow before directory submission. There are other important parameters like c class, IP check and others to get the maximum benefit from directory links. You can contact a good SEO company for proper submission services.

Last but not the least ? do not submit same anchor text and description in more then two directories. Use separate anchor text and description for different submission.