Garage and Estate sale bargains.

Finding bargains at sales can be a lot of fun and a great way to boost sales on your eBay auctions and store. Most of the time the sellers are more interested in reducing the stuff in their lives than turning a huge profit. This can be to your advantage in many ways. Estate sales are usually the greatest finds for the fact that the surviving family members have already picked their cherished items from their deceased relatives and are ready to get on with life. By selling everything, they will have less to deal with after the sale ends. Be sure to be mindful of their feelings and to not low-ball the items to much.

Garage Sales.

These tend to be seasonal for the fact that they are often held outdoors. Foul weather can prove to be an advantage here, if you choose to brave the elements. There are many hardcore buyers who will arrive no matter what the days forcast holds. It is important to not knock on the door before a sale starts because you could easily upset the seller and ruin a deal. You may be able to scope out deals while waiting in your car. Bringing your own box can be helpful also, it allows you to carry more finds and to bargain for a bulk buy. Don't be afraid to ask for discounts, especially if you are planning on purchasing many items at once. Remember that the seller usually just wants to get rid of it.
A more recent trend in garage/yard sales is to start on Fridays. Most people work on Fridays which reduces the crowds you might finds on the weekend. Getting to the sale at this time may prove to your advantage for the simple fact that the best stuff has not been sold yet. The prices might be less negotiable, but there will be items you just can't live without.

Estate Sales.

Estate sales are very similar to the garage variety with a few exceptions. Often times the family members are out to get as much money as they can. They may also be very hurt from their loss and have emotional attachment to certain items. Inexperience with sales may also be a limiting factor.
The family may have hired a professional who really knows the value of the items. They (the Pros) do their research and have to pay the hired help. This can be a disadvantage to bargain hunting. Again, they will be open to reasonable offers and may allow you to sign a best offer sheet. Be sure to ask if you will be tied into the sale if you do win the best offer. You may have to leave a credit card number to be entitled to this feature. Remember that they are Pros and will have a reputation to protect. Sign their notice sheet too, this will give you the heads-up on future estate sales.

End of Sale.

This is where the real bargains exist. Sure, most of the valuable and cool items may have already been scooped up, but the remainders will be real cheap. Almost any offer will be accepted. This usually happens on Sunday afternoons when the seller is either very tired or ready to send the rest to Salvation Army.  This might mean the you will make a second trip to a location so scout out well on Friday and consider if you think it will be worth coming back later. If the items seem to be over-priced on the first day, they may not sell until the seller realizes that items are not moving. Another Sunday advantage. Also be sure to check when the sale will be ending and give yourself at least an hour to haggle.

Resources.

Finding sales can take a bit of time, but these days there are a lot of resources.
The Wednesday or Thursday local newspaper will be the best for garage sales.
If you have a Thrifty Nickle in your area, be sure to look there. It's free.
Check Craig's List online. This is also a great source outside of garage/estate sales. Be sure to check the free items page too, lots of great finds here.
Many cities also have a free online community page. Bookmark these and check often.
Sign up sheets from estate sellers.

Tips.

A little trick I developed is to create a map to reduce travel time from sale to sale. I get a local map either online (Google maps) or out of the phone book and tack them to a foam core board. I will then place pins (the type with the large colored heads) on the map and route accordingly. The colored pins can be used for reference, such as time of sale (red pin = 8am) or if you decide to come back Sunday (white pin = return). This can save a bunch of travel time to and fro.
Bring your own boxes or bags. If you have extras, offer them the the seller. They may be very grateful.

Collecting.

Often times you may notice an abundance of like or same items from sale to sale. Purchasing these items and saving them may create great sales for you auctions/listings. An example would be frog figurines. If you keep running into a particular item over and over again, you may want to buy them and save for a later sale. Having 13 frog items may create an enticing auction or listing on your eBay. This can increase the overall profit of your minor purchases and make a frog collector very pleased to pay great amounts for a unique set.