While it is admirable that you will attempt to obtain coords that "aren't too far off", I view that thought train as flawed. True, not every GPSr will provide the same EXACT reading at the same spot, but when one starts placing and making placements with that highlighted statement in mind, they actually are operating outside of the guidelines. From the guidelines:
"2.1. Listing Guidelines that Apply to All Geocaches
1. Technical Requirements
1. Listings must contain accurate GPS coordinates. You must visit the geocache site and obtain the coordinates with a GPS device. GPS usage is an essential element of geocaching. Although it is possible to find a cache without a GPS, providing accurate GPS coordinates is an integral part of the activity and must be demonstrated for all cache submissions. For geocaches that include multiple waypoints, please see the additional guidelines specific to those cache types."
If you cannot obtain accurate coords, you shouldn't create the placement. This is regardless of whether the equipment used is at fault or some other factor is at fault. By listing "soft" coords, you are inviting cachers to trample and otherwise disturb a much broader area than necessary.
Although I am not "anti-phone" in the use of such for geocaching, I am "anti-phone" in placement of geocaches. My argument on this subject is two-fold. Firstly: these forums are filled with arguments of phone accuracy. Secondly: if you read the supplied guideline, you will note that it refers to a GPS device. Some feel that an iphone or the like qualifies as such. Well, I don't read it that way. Should the guidelines be altered or changed to include iphone and like devices, then my argument ceases. Until such time, I advise using a dedicated GPS device. Beg, borrow, buy or steal one.
If one enters into the realm of placements with the thought of "not being too far off", the objectivity of accurate listings are degraded.
That's why I plan to borrow my friends GPS device for the last part. Not a phone, GPS. But I'd rather try with the phone first to see what kind of accuracy I get. I added that last part because I've seen local cachers include the error margin of the hide +/- so and so many meters. If I can't get good accuracy I'd rather pick another spot for the hide, that's what I meant.