Disclaimer: I realise I wrote a lot here and it may not always be as easily understandable as I would have liked it to be. Please bear with me, and if you have any question about what the heck I meant, don't hesitate to ask 
I tried to pick up the bottom deal awhile ago and got no where.
May I ask which video you got?
Get the Daniel Madison BD Masterclass.
I second this. Daniel Madison's bottom deal is by no means the best there is, but it's a decent bottom deal, and a good one to start with. There are several reasons why I'd recommend you to get this video:
1. It's a good bottom deal to begin with because it's a lot easier than most others. This allows you to learn certain principles of the bottom deal without completely despairing over the mechanics of the deal.
2. Mr Madison tells you to develop your own grip. This is very important, so I'll say it again: Develop your
own grip! And, just to drive it home: Develop
your own grip!!
The bottom deal is a move that must be highly personalised to suit your
own hands. No two people have the same hands. The picture you posted above is a great example: It looks as if LeBron James had told you exactly where his contact points are when he holds the deck. This might suit him, but - ignore this if you have the hands of a 6'9" basketball star - there's no way the same will work for you. (I'm sorry if I'm sounding harsh. I'm taking a lot of freedom when writing because I vividly remember being exactly where you are right now.)
This is the most important thing Daniel Madison can teach you: His grip is
not the non-plus-ultra. You're not
supposed to copy his grip exactly. They say imitation is the sincerest kind of admiration, but in this case imitation only results in frustration, and possibly hand injury induced by excessive strain.
When you're fairly proficient (not mastered, but at a point at which it feels more or less comfortable) with the Madison bottom deal, I'd strongly recommend you to move on to Jason England's download from T11. It goes into a lot more detail regarding several kinds of bottom deal (Erdnase and mechanic's grip) and will help you learn a more advanced bottom deal.
That said, let's have a look at your grip. RealityOne already gave some good tips on how to make it more natural, but here's just a few extra pointers:
Hold your hand flat (palm up, fingers outstretched, thumb at a right angle to the other fingers) in front of you. Lay the card deck on top, so it's at a right angle to your outstretched fingers. The center of the deck (lengthwise) should run above the knuckles connecting your fingers to your palm. The tips of your fingers should be about 1/2 inch apart from each other. (If you closed your fingers now you'd have the full grip: all four fingers along the side of the deck.)
Now, rotate the deck a few degrees clockwise, until the front right corner is between your index and middle finger. If you close your fingers now (don't clamp, just lightly curl your fingers around the deck), you'd be in the mechanic's grip.
Rotate the deck another few degrees clockwise, until the front right corner is between middle and ring finger. Again, close your fingers (the fingertips of your ring finger and pinky should just protrude above the top card). Adjust the deck a little bit so it sits comfortably in your palm, and congratulations, you're in Erdnase grip.
So what' the difference between the original Erdnase grip (the one you're trying to simulate in your picture) and what you're doing now? Your ring finger and pinky are spaced more evenly across the side of the deck and don't curl around to the top of the deck, your middle finger is just left of the corner of the deck (instead of exactly at the right corner) and your index finger lies more naturally across the front of the deck (instead of being exactly at the left corner). All of this results in a more relaxed and casual grip, as well as some advantages when bottom dealing.
Even if you exactly followed the instructions above, I doubt the grip you are in right now and mine are exactly the same. But both of them would be classified as Erdnase grip (variation). So the lesson we learn from this: If you read or see the description of a specific grip, adjust them to fit your hands. "They're more what you'd call guidelines, than actual rules", to quote Pirates of the Caribbean.
The best grip for the bottom deal should be dealer's position /mechanic's grip (see the description in Volume 4 of Card College).
I have to disagree with this statement. Yes, you can deal a good bottom from this grip, but you can't say it's "the best". You'll find some tremendous bottoms dealt from the Erdnase (see Steve Forte TV Special), the mechanic's (Jason England), full (Peter Duffie) or straddle grip (sorry, didn't find a video).
Nevertheless, some grips are more suitable than others. When you progress, I'd recommend you to move away from the Erdnase grip, as it's a very unnatural way of holding the deck. However, if you're performing for lay audiences they won't notice, and probably wouldn't give a **** if they did.
Apart from this caveat, it's completely up to you. Learn the basics (again, Jason England's video is great for this) and, going on from there, develop your own deal. Play around with different grips, adjust each of them to suit your style and your hands and experiment. But remember: For this to work, you need to know the fundamentals!
This post has gotten longer than I thought, and might be a bit confusing at times. But one thing that should be made clear at the end is what's most important: Have fun practicing! The bottom deal is a difficult move, but it's great to be able to do. So don't get discouraged and keep asking questions if something isn't clear
