Assalamu alaikum wa rahmatullahi wa barakatuhu!
In the Name of Allah, Most Gracious, Most Merciful
1. Make a big effort to increase all your religious activities for the last 10 days, such as extra prayers and more Dhikr.
2. Keep reciting this special dua:
Allahumma innaka 'affuwwun tuhibbul 'afwa fa'fu 'anni
O Allah, You are indeed Forgiving and You love to forgive, so forgive me.
3. Make Tawbah (sincere repentance).
4. Evaluate yourself and see how you could be a better person.
5. Make long and sincere duas.
6. Spend quality time with your family.
7. Try to finish the Quran and read the dua for the completion of Quran recitation.
8. Spend some time in Itikaaf.
If you cannot fulfil the Sunnah of sitting in Itikaaf for 10 days then you can sit in seclusion for any length of time with the sole purpose of drawing closer to Allah and you will, insha Allah, be rewarded accordingly.
9. Try to minimise the time you spend on worldly matters. You could try not watching TV, listening to music or surfing the internet for this short period of time and this will all help you in drawing closer to Allah.
10. Try to memorise some of the shorter Surahs in the 30th Juz which you can recite in your salah.
11. Read and learn some hadith and try to practice these in your daily life.
May Allah give us all the ability to do our best in these last few blessed days - Ameen!