First: Focus on the big players
To break down a massive keyword list into more manageable pieces, consider starting with the keywords that receive the most traffic or represent your client's most popular products. Create ad groups with customized ad text for these top keywords, rather than writing specific ads for every product your client offers.
For example, let's say your client sells DVDs. You can create ad groups for the top ten movie titles per genre and write specific ads relating to those keywords.
Second: Organize the rest
What about the rest of the keywords that are more obscure or aren't as popular? Here are some options to effectively manage those:
Lastly, be sure to test various approaches to keyword management to find the optimal method for you. For more tips on managing your keyword lists, visit our Help Center.