These are a few tips one should never do when doing SEO and avoid getting banned.
1)Too much link building from start via link farms,Link exchange
2)Avoid reciprocal link building if the site is from not the same niche as yours
3)Avoid paid links google hates paid links
4)Don't have duplicate contents on your site as this will lead you to nowhere.
5)When submitting to directories and article directories try to do it manually not automatic
Hope these tips work great for you
Cheers

And avoid black hats. It works but it is not for forever.......

Thanks for sharing some valuable tips...