CVBJ
This works well. But real decks are different. It would be nice to have a "photo-realistic" discard tray that could be precisely sized so that no matter whether you use a 12.4" laptop screen or a 20" LCD, that the discard tray appears to be a "true size".
That said, estimating cards is only a part of the problem, actually a pretty small part. Much harder is using that estimation to turn the running count into a true count for betting/playing. And there CVCX just can't be beat, because you can set it to nag you for every incorrect playing decision, whether it be BS or BS departure, every betting error, even if you choose to use a complex cover betting scheme for longevity.
You can generally buy real casino cards cheaply enough. Or you can ask a pit boss for a deck which they will generally give to you, acting like they are giving you a big comp when it costs them very little since they will be giving you a used deck most of the time... You need to practice some with real cards, but then CVBJ can hone the rest of your skills sharp enough that you might even cut yourself. :)
If you are interested, here is what I have done:
I have 6 decks that I use for a shoe game. I took 52 cards, plus a piece of waxed paper on each side, and clamped them together (not horrendous force, just firm) and I then used a drop of thin CA (superglue to the non modelers out there) touched to the side of the deck at each of the 4 corners. This thin CA glue will "wick in" and cure, and now you have a "solid" deck of cards that are bonded for all time. Do 6 of them, and you can do deck estimation all you want. Then you can use non-bonded cards with a helper, by letting him pick up part of the stack and you estimate how much is left. You can then use your "solid decks" as a quick measuring stick.
For DD games, I use 1/2 deck accuracy, and as you might guess, I have 4 1/2 deck "bricks" of super-glued cards. This is less challenging although it gets interesting right around the 'boundary' of "is this closer to 1.5 decks or 1.0 decks? After practice with the "bricks" you can do the same drill with a friend letting him sit 2 decks on the table and picking up some chunk of them. Your task is to estimate what is left.
I've practiced enough that I don't estimate "what is left" any longer, I automatically estimate "what did he remove" since that is the part you need for TC conversion anyway.
If you play at the real tables, and using CVBJ, it won't take long before you won't be thinking much about this part of the process.
BTW, the waxed paper is to keep the superglue off of the "clamp" and your hands. It is tough to estimate decks with fingers stuck to them, and thin CA _will_ bond skin to anything, including itself... Also give the glue plenty of time to "fire". It doesn't "dry" or "cure" like normal glue, so it can sit dormant for a bit between cards and waxed paper, just waiting for you to pick up the deck and "bond" with you. :)