Our Mother Hadhrat Ayesha RA mentions that the Prophet (SAW) would not fast more in any other month outside of Ramadhan, as much as he did in Sha'baan.
We also learn from narrations that our Beloved Prophet (SAW) would usually fast twice a week (Monday and Thursday).
He would also Fast for 3 days every Islamic month (13th, 14th, and 15th).
We have a great opportunity to combine all these Sunnahs and to gain immense reward.
We should make an intention to fast on these days, which corresponds with this Sunday 31st May, Monday 1st June and Tuesday 2nd June (in the UK).
Fasting on these days will serve as a preparation for Ramadhan. The fasts will also be a means of us acting upon the Sunnah of Fasting in Sha'baan, Fasting in the middle days and Fasting on Monday.
May Allah grant us the strength, abiility and tawfeeq.
Shaykh Abdul Raheem