EA should give first BUY signal after that:

1)price touches lower bollinger band and
2)then there is a buy signal from trend indicator (green arrow)
next buy orders after that:
1)price touches medium bollinger band and
2)then there is a buy order from trend indicator (green arrow)

Same but opposite for sell signals (using highest and medium bb and red arrows)

First signal at fix lotsize.

Following signals using a % of decrease (example: first buy=0.10 lots, %decrease = 30, 
second buy = 0.07, third buy = 0.05....)
Number of oders of basket to be limited for each cycle of trades (2,3,4,5...).

Take profit using amount in money for all basket.
Fix SL for each order.

I will give direction of trades manually in option windows (so that EA will operate only buy or sell)