Bismillah
How to start preparing yourself mentally for Arafat,
the day Allah SWT frees most people from the fire.
Suggestions are:
1. Sleep early the night before, to strengthen yourself for this special day.
2. Wake uo before Fajr for Tahajjud and Suhoor.
3. Make wudhu, while conciously remembering that your sins are being washed away til the last drop of water. Pray at least 4 Rakat of qiyam and make du'a for your deen & dunya in your sujood. Cry to Allah SWT, showing Him SWT humility & ask Him SWT to give you tawfeeq on this great day, and thank Him SWT for making you of those who would experience this special occasion.
4. Spend some time (10-15 min at least) making Istighfar before Fajr, to be like the righteous whom Allah SWT described as "seeking forgiveness before dawn".
5. Repeat after Fajr adhan & make du'a. Pray Fajr. Sit in your prayer place and do your morning adhkar. Make tasbeeh, tahleel, tahmeed & takbeer. And as the Prophet SAWS advised, increase in "la ilaha il-lallah, wahdahu la shareeka lahu, lahul mulk wa lahul hamd, wa huwa ala kulli shay'in qadeer".
6. 1 minutes after sunrise pray 2 rakat of shurooq. This all mounts to the reward of a complete Hajj & Umrah, so do not waste it!
7. If you're able to stay awake by all means, do so and do not waste a single minute. If you need to sleep, take a nap for an hour with the conscious intention of energizing yourself for the worship of Allah SWT.
8. When you wake up, make wudhu and pray at least 4 rakat of duha. Then recite lots of Qur'an and make the dhikr mentioned above with breaks in between. (Make dhikr after Dhuhr as you prepare food or as you do what is absolutely necessary)
9. After 'Asr, say the evening adhkar. Then recite Qur'an again til about an hour before Maghrib. At that point, make LOTS of du'a til Maghrib, while having Yaqeen that Allah SWT will answer. (Preparing a du'a list ahead of time helps!) Beg that the day will not come to an end except that Allah SWT has forgiven you all your sind and written you of those He SWT has freed from the Fire. Don't forget the Muslims suffering all over the world. Remember as you break fast that your du'a at the moment is accepted.
May Allah SWT grant us all tawfeeq on that day, may we be of those who are freed from the fire and may He SWT accept our du'as and the du'as of all who will be standing in the plains of Arafat
Ameen wa rab-bil alameen