Instead of saying 'Maa shaa Allaah' (Allaah has willed), you can say 'Maa shaa Allaah wa ta‘aala' (Allaah, The Exalted, has willed); instead of 'In shaa Allaah' (Allaah willing), you can say 'In shaa Allaah wa ta‘aala' (Allaah, The Exalted, willing); instead of 'Subhaan Allaah; (Glory to Allaah), you can say 'Subhaan Allaah wa ta‘aala' (Glory to Allaah, The Exalted); instead of 'Astaghfirullaah' (I seek the forgiveness of Allaah), you can say 'Astaghfirullaah Al-‘Azeem' (I seek the forgiveness of Allaah, The Almighty). Is there any other way to say 'Allaahu Akbar' (Allaah is The Greatest), like 'Allaahu Akbar wa ta‘aala' (Allaah, The Exalted, is The Greatest), or anything else? Also, what are other ways of saying things like 'Allaahu a‘lam' (Allaah knows best)?

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger. 

This question involves some kind of pretentiousness (asking long-winded questions), and a person should not overburden himself with such a thing.

In principle, the Athkaar (pl. of Thikr [expressions of remembrance of Allah]) should be said as they have legislated, without any additions or alterations.

The fatwa of the Standing Committee reads, "With regard to the supplications and the authentic Athkaar, the basic principle is that they are determined by the Revelation (Quran and Sunnah) in regard to the wording and the number; so a Muslim should abide by this; he neither increases or decreases a definite number nor adds something to the wording or deletes from it, nor does he make changes to it."

Based on the above, if a Muslim wishes to say authentic Athkaar that have a specific wording, such as 'Subhaan Allah', 'Astaghfirullah', or 'Allahu Akbar', then he should not add anything to them.

However, if the person did not intend to say the authentic Athkaar, then he may add any words of praise that he wishes to them.

It should be noted that the wording 'In shaa Allah wa ta‘aala' is problematic in its structure, so it should not be said.

Allah knows best.