I'm glad you found that helpful. Speaking of period settings, John also has some suggestions on how to set up your 'supporting' indicators. He's discussing this is terms of the Money Flow Index that he uses, but it applies to any confirming indicator, especially the oscillators.
We’ll use the basic Bollinger Band settings of 20 periods and ±2 standard deviations. To set the MFI parameters we’ll employ an old rule: Indicator length should be approximately half the length of the calculation period for the bands. Though the exact origin of this rule is unknown to me, it is likely an adaptation of a rule from cycle analysis that suggests using moving averages a quarter the length of the dominant cycle. Experimentation showed that periods a quarter of the calculation period for the bands were generally too short, but that a half-length period for the indicators worked quite well. As with all things, these are but starting values.
Bollinger, John. Bollinger on Bollinger Bands (p. 157). McGraw-Hill Education. Kindle Edition.