The best way I've found is to keep a decent size jar (holds about 1 1/2 dozen shells) under the kitchen sink. This is as close as you can get to where the shells are cracked and ready to start drying. When this jar is nearly full, I simply dump it into a 2.5 gallon bucket in the dryest spot in the house. About 2 days later they are dry, so I crush them with a wooden mashing block I made specifically for this purpose. I will then leave them in the bucket and crush others on top until the hens need more or the bucket is full, whichever comes first. Remember they do not need to be powder, but crush them to bite size pieces. Either mix it in the feed, or give free range, just try not to let them run out. If you sell eggs you should additionally feed oyster shells as well. I do not see any need to bake in oven and blend or food processor, as this does the same job, but takes more effort. This is only nessesary feed to laying hens, but won't hurt roosters or young.