Hello,
If you tell us what sections you gave yourself points, we may be in a better position to help you in terms of documents required.
The important thing is to prove that you have 75 points. Like for anything else, preparation for HSMP takes a lot of time and effort.
For the sections where you gave yourself points, collect foolproof evidence in the format the UK HO requires - E.g., 12 month salary slips on Company letterhead / or else signed and stamped by your HR team, your IT return for the same period, age proof in the form of a notarised Driving licence or notarised copy of your passport, etc.
Once you have the documents, you can apply and hope for a favourable decision. You may want to go through the caseworker guidelines for the requirements of evidence. The link is as follows:
http://www.ind.homeoffice.gov.uk/docume ... kguidance/
Also, please note that the HSMP format is on the verge of another change. Nobody in the forum is really certain what the changes are... so you may have to wait and see... however, you may still apply on the curreny basis until the new rules are in place.
All the Best!!