How do the believers (God-fearing people) protect themselves from evil thoughts?

Verses 200-202 of Chapter 7:

And if an evil whisper comes to you from Shaytan, then seek refuge with Allah. Verily, He is All-Hearer, All-Knower. Verily, those who have Taqwa, when an evil thought comes to them from Shaytan, they remember (Allah), and (indeed) they then see (aright). But (as for) their brothers (the devils' brothers) they (the devils) plunge them deeper into error, and they never stop short.