[nilliraq]

Assalamualaikum wa rahmatullahi wa barakatuh.

Brother Im not sure what Fiqh you follow but if you are Hanafi, the bare minimum for ghusl to be valid is the following
1. washing mouth
2. washing the nose (sniffing water until the hard part and blowing it out)
3. washing of the entire body.

There are many sunnahs as the brother above mentioned and you can learn this from your local scholar or books such as Ascent to Felicity which you can find on alrashad.com.

Once you have done what is needed for ghusl and wudhu, ignore all mere possibilities especially since you are having waswassas because when one is in such a state he cannot think properly and check surah naas(last surah of Quran) and you will find that, we seek protection from the whispers of the devil, so succumbing to his whispers is not allowed.

In general the way of the sunnah is to be easy going in manners of Tahara(purity). you can read about that here... http://ghazali.org/books/purity.pdf
and for a reader on waswasa here is a link.... http://seekersguidance.org/ans-blog/...ss-misgivings/

waAllahu Alam
ZF