It depends on your appetite for risk and the quantity of coins you are mining. With our scrypt mining activities our management software (CipherMiner) places sell orders in the middle of the spread. That has proven pretty reliable for selling the quantities we were generating with 20+ MH/s.
When I tried it selling just below the lowest ask (semi-equivalent to Cryptsy's "Sell at top sell bid (Higher Pirce)"),it sold most of the time but I did have to check every day or so and "clean up" trades which had been missed due to a fall in the market.
However, the "middle of the spread" strategy has not worked well for the SHA256 coins though because with 5 TH/s we were swamping the volumes a little bit. Instead I've currently got Cryptsy set to sell at the highest bid price ("Sell at top buy bid (Lower Price)"), and that has been 100% reliable so far (CipherMiner's trading function is offline for some upgrades).
If you want a fully automated solution you can just check in on once a week then I'd suggest the above.
It is a shame that neither Cryptsy nor BTC-E support automated withdrawals yet (even via their APIs, despite listing the functionality) since with that too and a simple bot you could withdraw from Cryptsy to Gox or BTC-E and use something like ButterBot to mange your BTC (ie. selling it to USD if the market falls).
Kate.
Well I guess it is "Sell at top sell bid" I rather check my account once a day than to be stuck on the screen all day trying to sell at the right time. I do use an app on my android phone to alarm me for highs and lows, but I'm mostly on my laptop, and I get very tempted to pay attention to the market because I think I'm going to miss selling or buying at the right time. I'm a student in computer programming, however bots are something foreign to me but I will check them out, they might be of great benefit to me. You are very pretty an very smart woodrake, If you wouldn't live so far away, I would invite you to a coffee. Have a nice day and thanks for the advice.