There is no 100% safe advice for winning, but some tips can help:
1. Be sure that you have enough TC credits ( in my opinion not less than 20 )
2. Do not immediately decline the offer ( Wait to see how the auction takes place )
3. Look at previous auctions, what is the average value of the goods to which you want to bid
4. Do not wait until the last second because of possible bad internet connection
5. Keep your fingers crossed (optional)