If you have entered the realm of DSLR photography in the last few years what mistakes did you make and what would you do differently if you could go back in time?

For me...
I would have bought Lightroom sooner and spent more time learning how to use it properly.
Also bought a monopod with a simple head to support my 75-300 lens. I have found the set up to be difficult and annoying. Should have saved my money and bought a good tripod & ballhead instead.

I would have bought a 24" printer instead of 17".

Peter

I would have waited for the Epson 3800 17" printer rather than buying a HP B9180. (I like the 9180. Ink is cheaper on the 3800.)

That's a really, really, good question. I think my gitzo carbon fiber tripod and acratech ball head are the two best photographic purchases I've made. Also, I really like my canon 17-40 f4, eye one display 2 calibrator, nexto 2700 backup device, photoshop cs4, and building my own computer. I like luminosity masks a lot. Do they have those in lightroom?

I like my gear, but the places I've been and photos I've taken are priceless. Just remember, the photos you take tomorrow will be with the equipment you have today, or something like that.

My only significant mistake was getting a cheap aluminum tripod that would wobble too much in just a slight breeze, before I threw it out in disgust and got an expensive Gitzo (which was what I should have gotten to begin with).

Lisa

Just stayed with MF film for quality stuff(which I now am doing again). Bought a small pocket camera for home photos and the like.

Bought better quality insurance that actually pays out when sh*t happens. Sorted out file management earlier, bought a film scanner whilst they were still available.

I think my worst mistake was that the first dozen or so times I heard the phrase "Color Management" I never bothered to ask anybody what it meant. In 50 years of B&W darkroom work, I never needed to know anything about that. I wonder how many hundreds of dollars of wasted materials and hundreds of hours of wasted time I might have saved if I had only asked.  

OMG. How could I forget about file management. At least doing minimal keywording on import...

Oh, yeah. Buying at least a Pantone Huey is a must.

Not getting a puck of some sort is like buying your tripod from best buy.

1. Should have bought a Gitzo tripod sooner, now have a collection of crappy tripods in the garage.
2. Should have bought L lenses from the start rather than trading up.
3. Should have set the alarm for really early more often

I couldn't agree more with you Plekto! If I could do it all over again, I would have invested in MF film from the onset, and spend the money on a decent scanner, software, and film holders.

To answer the OP's question though, I would have, like some others, invested more in a stable platform - carbon fiber tripod, good ballhead, and quality glass. I made some abysmal lens purchases early on, thinking I could save a few extra bucks. Big mistake.

Yeah, 80% of what I shoot is actually family and trips and so on and my old Minolta pocket digital camera still works great for that. Trying to be a techno-geek and "cool" and all of that carrying around a DSLR for such mundane tasks is silly. If I had to do it all over again now, I'd just get a small "prosumer" 12MP camera that I could fit in my pocket, or maybe something like the Olympus E420 because it's also tiny.

The other 20% - the stuff I obsess over, is all film - almost all black and white, which digital still hasn't quite caught up with. I personally love the way film handles it and how it gives a timeless look to the subject. My sister was amazed that I ordered only prints form her wedding a few years ago that were black and white. Until she saw them framed...

Oh - my advice in any case to a newcomer is to buy one truly good prime lens at first and use it for everything for at least six months.(you'll probably not be able to afford another lens anyways - heh)

While I did buy L lenses to start with, I would have bought faster L lenses instead of thinking I could get away with the more economical f/4 glass instead trading up to f/2.8 after the fact. I also would not have made a couple of impulse buys for "good deals" on lenses that looked good on paper (when in real life they actually look pretty darned soft).

Lastly I would have not bought any fairly expensive used lenses without a seller that is willing to take them back when it turns out they have problems -- ya, like that is likely to happen when you're not dealing with a reputable store (I still have a lens in with Canon repairs 9 weeks later and waiting -- 3rd try and hopefully it's actually SHARP using AF this time, sigh -- kind of sad when they say that the AF is perfect and I can still do MF in the tiny little viewfinder sharper than their brand new AF they installed)

Though it applies to film photograhy too, as others noted, I also made the tripod mistake. I thought I hated using a tripod until I got my Gitzo along with a Really Right Stuff ballhead ( http://reallyrightstuff.com/index.html ). Adjustments are so incredibly easy and my photos improved a lot. If you're doing landscapes or stills, a a nice tripod and ballhead is well worth the money.

I'm pretty much a beginner myself, especially with printing, but...here are my thoughts on this after my experience with the 3800 for year... if you're just starting printing, I think it's easier to start learning digital printing on gloss and semi gloss papers. I started doing a lot on matt because I knew I didn't want glossy, and my prints looked like %^$^&^&. Now I do test prints on cheap glossy paper to get an idea of what I might have, and then work from there.

Finding the right paper for the look you want seems to be one of the most important things. For printing, I found reading Eric Chan's website and articles for the specific printer I'm using, (Epson 3800) was one of the most useful things I ever did.

Also for printing, print a ton and don't be afraid to waste paper at first.

And my latest, what I'd consider has been my biggest mistake....I take very many vertical shots and never printed them large. Until you print the standard 3:2 ratio large, the skinniness of the print might not be obvious to you. So now, I have a collection of fav. photos that can never be printed large. I'm attempting to crop 1/2" off the top of each, but it's hard to give up a 1/2" after you've grown attached.