To be assured of a dua's acceptance, the dua should indeed begin with praise of and thanks to Allah (God). Then we should ask Allah (swt) for His rehma and blessings on the Prophet Muhammad (saw). Then we make our dua. Then we end it with Ameen.
Prasie (Subhanallah), and thanks (alhamdulillah) are a form of dhikr (remembrance) of Allah. Whatever we do, we can keep praising and Him. We are encouraged to do the dhokr of Allah at all times by saying one, more or all of these:
Subhanaalh (Praise to Allah)
walHamdulillah (and all Thanks are to Allah)
wa la ilaha illah (and there is no deity other than Allah)
wallahu Akbar (and Allah is Greatest)
wa lahawla wa la quwwata illa billah (and there is no power to do good and refrain from vice other than from Allah)
and as the previous reply said, you can do these in any language.
Remembrance will gain you merits, and raise your status in the Hereafter.
Hope this helps.