assalamu alaikum :o)
Then you go down in prostration. This is the highest level of submission, for you are bringing the most precious part of your body, namely your face, down to meet the most lowly of all things, the dust of the earth. If possible, you should make your prostration directly on bare ground, this being more conducive to humility and a sure sign of self abasement. When you place yourself in this position of lowliness, you should be aware that you belong there. You are restoring the branch to its root, for of dust you were created and to dust you shall return. At the same time you should renew your inner awareness of Allah’s majesty, saying: “Glory to my Lord Most High!” Repeat this to add confirmation, for saying it only once is not sufficiently emphatic.Source: The Inner Dimensions of Prayer by Muhammad al-Ghazali.
When your inner feeling has clearly been refine, be confident in hoping for Allah’s mercy. For His mercy quickly flows towards weakness and lowliness, not towards arrogance and vanity.
As you raise your head, say “Allahu Akbar!” and ask for what you need, making the supplication of your choice, e.g. “My Lord, forgive and have mercy! Overlook my faults of which You are aware!”
You then make a second prostration, reinforcing your submissiveness.