Good photographers try to be prepared for almost any contingency. Unfortunately, if you tried to carry everything you'd need to meet every contingency in the field, you'd have to pack like a Bedouin trader. Many times that simply isn't possible and other times it's not desirable. So the seasoned photographer learns to be resourceful. Here are a few miscellaneous tips that can save your back, particularly on short trips near home.
In all but the most extreme lighting situations a monopod can substitute nicely for a tripod and is a lot easier to carry. With practice you'll be able to hold a monopod nearly as stable as a tripod, for a short time anyway. Another trick for stabilizing a monopod is to wrap the camera strap around your upper arm and push on the monopod while exerting gentle backward pressure on the strap. Similarly, you can place a large clamp on your monopod and use it as a shoulder brace, almost like a gun mount. It might look a little funny but it works surprisingly well.
Working In Sand
For those times you have to drag a tripod to the beach or sandy area, grab three tennis balls on the way out the door. Cut a hole big enough for your tripod leg and fit a tennis ball over each end. The tennis balls won't sink in the sand, will keep most of the grit out of the end of your tripod leg and you can throw them away when you're finished.
Another great thing about working at the beach is you don't need to carry sand bags, just bring bags. There's usually plenty of sand already on the beach. Those are priceless for weighting reflectors, which tend to act like a sail in ocean breezes.
Bring A Cooler
But leave the ice packs at home. A cooler has several advantages over an equipment case in many situations. They're solid, many have a handle and wheels, and you can sit or stand on them in a pinch. If you lose or break it, you're only out about $40.
You can still carry drinks with the camera gear, but carefully. Get those drink cozies you put in the freezer. Those will keep your drinks cold without bringing down the temp too much in the cooler. The last thing you want to do is bring cold optics or a camera out into warm, muggy atmosphere. Expect instant condensation if you do.
Carry a Bag of Rubber Bands
They're just so handy for so many things and so easy to carry. You can use them for emergency repairs and to keep papers from flying away. A fat rubber band is handy for dislodging a stuck filter. Wrap the rubber band around the edge of the filter and that should give you enough grip to get it loose.
And, if you're stuck waiting outside a courthouse waiting for a photo op, they're also endlessly entertaining for taunting your fellow photographers.
Incident Light Meter
Many photographers still carry a light meter, even in the days of high end digital SLRs. If you're packing light you can use a styrofoam cup over the end of your lens and use your camera's light meter, hold it in place with one of your rubber bands. Note that cups do come in different thicknesses, so you may want to calibrate yours using the Sunny 16 rule before you leave.
Record the exposure at the subject, then walk back to shoot the picture.