If you are trading just one pair, I would place more than one order per direction. Say 4 buy pings and 4 sell pings. Look at the market and try to guess what could be a reasonable price range (max and min) for the next hours-days (good luck with this).
So over the next few days I believe the high for LTC/BTC pair on Poloniex will be .021 and the low to be .0198 what would be a good 4-4 proposal?
Buy: .0198, .01995, .0201, .02025
Sell: .02055, .0207, .02085, .021
As a minimum you should create a stop loss wherever you feel comfortable with, and rise Min % Garanteed Gain a bit. What is a bit? Well, it depends how wide is the range you guessed and how expensive are commissions and fees in your exchange/market. LTC is not one of the currencies with widest daily ranges. I would try with 1% and see how it goes.
So if the current price is .0204, set a stop loss at .0204 - (.0204 * .01) = .020196? This would contradict my prediction above.
Yeah, that spread of prices looks ok to me, although as I told you before your guessed range is pretty tight, it is only a 6.06% price variation, although it may be realistic for LTC (CAT works better with coins having some more wider ranges). Maybe you can replace the two central prices (highest buy and lowest sell) by the CAT proposed prices which will execute faster. Note that current price has moved already since you wrote your post, so take it into account.
Market seems to be recovering from a dip right now, so it looks bullish today. You may also consider to place 5 buys and 3 sells, it is up to you. Bullish -> better ping buy. Bearish -> better ping sell. What I mean is that maybe both your predicted high and predicted low, are too low. EDIT: forget about this paragraph, recovery is not that clear.
https://ibb.co/nvMbVF Last 70 minutes.
I think you are mixing the Stop Loss with the Min % Guaranteed Gain. They are two completely different things. The M%GG should be around 1%, but your stop loss should be larger, otherwise it will be executed soon for sure, and you do not want that. You prefer to maintain your pong order some more time in the market just in case the price turns around and the pong order is finally executed at the target price (with a gain). The stop loss should only be executed (with a loss) when you are almost certain that the order will never be filled because it is clearly outside of the market, and you want to stop the bleed. I use a -20%, but you can use whatever you feel depending on the risks you want to take. I would say minimum is -5%. You can declare it in the Market Parameters tab as a negative percent, and would apply to all pong orders.
You have to bear in mind that placing orders in both directions will always result in one of the directions being out of market sooner or later, and that will cause you a certain loss when stop loss executes. The idea is that your gains in the other direction are higher than your losses in the wrong direction, by exploiting the oscillations that the price will have when trending up or down.
Do not take my word as the bible because I may be wrong too. Make your own decisions. I do not want to be blamed if your loose some money, the markets are really troublesome these days.