What i do is limit inquiries to 6 per 6month rolling period. So no more than 6 during any 6month period.

Also I try not to cancel my cards. I call them and ask them to switch it over to non annual fee cards with that bank. Sometimes they'll do it sometimes they wont. You need cards with long history.

I try to maximize credit limit on cards I'm going to keep (switch over to non-annual). Never decrease this limit from original. I've notice that they report max point. So say, you had $10k limit at begining and used to spend upto $5k. Then ask to reduce this limit to $4k. Credit report will show limit credit card $4k, Max spent $5k. Not good.

Always keep more credit cards that you do not churn, than those that you do. I have around 10 no annual fee cards, and about 8 annual fee cards that I would like to cancel before annual fees are due.

I have some cards over 10 years