Really to be strong with SEO you need to be fully focused on ensuring you stay quality by contiuely protecting your efforts. For example, your competitors can easily check your sites backlinks and target the same links.

Be sure that the links you get are not easily obtained. The easily obtained links are usually the ones that are not quality and will easily be scraped up by your competitors.

So there are 2 ways to stay ahead of the game, either go full speed and fast when getting to the top, so even when they do try and follow and chase your links you are already too far ahead. Or go slowly and steadily and cover yourself at the back of what you do. Alot of smart SEO guys do just that. They join in forums for example but they do not add a signature link in their posts. The reason why they don't add a signature link is so that they don't have their competitors track their every move.

The Easily Obtained Links:
Sites that say "Advertise here" add your link here" are prime examples of easily obtained links.

The More Discretely Obtained Links:
Partnering or specifically contacting quality sites and asking them to allow you to sponsor them.

Either way you go about it, just be quick and smart, don't let fear hold you back too much, as with SEO time is never on our hands and time is very precious. If you are not sure about what you are posting and which site you are posting a link on where your competitors can follow then leave it and go to the next task, but make sure it get's done.

When joining groups, forums or communities a very useful tip is try mixing up your usernames, for example if in one community you use the name joeblow, make the other community you join something totally differnent. This way competitors can not track your username in search results to precisely. Mixing it up is good and more confusing for followers.

Another thing is if you target specific keywords competitors will always be able to check the keywords you are optimizing for in your source code. Obviously when you are good with SEO, particularly on-page SEO you do not have to use keywords so precisely in your meta. I have seen sites rank to the top without using keywords at all in the source code. This can only be achieved if you are highly experienced with off-page optimisation.

If you are very good with off-page optimisation your users will not see what you have done if they usually are used to checking on-page that is, and if you are better with on-page and your competitors are checking your off-page efforts then go as crazy as you like. I tend to use no-follow attribute where and when I can, both off-page and on-page to keep myself covered.

So when slapping on the SEO Sunscreen don't just put the sunscreen on the areas that you think you will get burned. It's important you put sunscreen all over. This way you will not only keep your competitors away but you will also keep Google and other Search Engines from any kind of penalty. This might include dupicate content penalties, cloaking what ever the case may be, just work smart and effectively and good luck!