How to leverage Brokerage Account in 401(k)

[InvestoGuy]

Hello All,
My 401(k) provider gives us the option of a Brokerage Account through the 401(k). I use that and have setup Vanguard ETFs per my AA.
Currently, my bi-monthly 401(k) contribution goes to the non-brokerage side of the account, in which I have picked Vanguard equivalent funds that are available. 20% of the total account value has to be in the non-brokerage account. Once every 12-18 months I sell those funds and move the money into my Brokerage Account where I then re-buy Vanguard ETFs based on my AA. I do see the risk of losing money due to market fluctuation in the interim. I am charged $8.99 per trade in the Brokerage account. So my question is, how do I most effectively leverage the Brokerage Account to:
1. Minimize the $8.99 transaction fees
2. Minimize losing money due to market fluctuation during the move from regular to brokerage account

Anyone in the same boat? Any best practices?
Regards.

[billern]

1) trade as infrequently as possible (to the extent the trading fees exceed the difference in expense ratios)
2) I wouldn't worry about it