Alhirey, in all honesty, I can write a 100-page e-book or report to answer your very general question. But since you asked with a general question, I'll just give a general answer.

How to Stay in the Top 10 Position of Google
1. Make sure you choose keywords that meet these parameters:

• Low Competition
• Global Monthly Searches (GMS) of at least 5000
• Cost-Per-Click (CPC) of at least $1.00
• At least 30 daily searches on Google
• No more than 150,000 competing sites

I am not an SEO expert so I stand corrected if any of the SEO experts in this forum will correct me in that part.

2. Write quality content. This word "quality" means a lot depending on what you're trying to achieve. The content should be informative and somewhat sales-y in style and tone if you're aiming to sell affiliate products.
On the other hand, informative content will do if you're just trying to earn through AdSense. As a rule of thumb, always try your best to come up with an intriguing title and/or content. It's either you start or end your article with an intriguing declarative or interrogative sentence. In most cases, that strategy invites your readers to comment or bookmark your website.

I hope that helps.

Never stop the SEO which you are using. If you have not used SEO Services then continue with them to maintain your position.

You want to maintain your ranking in top 10 positions, it means you're already ranking on 1st page.

So the best way is to continue build relevant and quality links from related niche sites. Now you must looking for the ways to build them. So my suggestion is choose yourself, I mean what works for 1 niche probably won't work for other niche. So you need to check which technique is best to acquire such links. You can do article submission, blog posting, guest posting, ppt creation, PDF submission etc. I would suggest stay away from directory submission and social bookmarking as most of these sites are waste of time.