I think it is good habit in general to play the keys at the front end of the keysticks. The closer you get towards the fallboard, the less control you have - unless you are playing an expensive grand piano with really long keysticks.
Also note the thumb on my last picture. I got used to this way. When the thumb plays a white key with other fingers are spread away, it allows to get a bigger reach. If I play a 10th, I must use the thumb in this way.
WieWaldi That's good advice WieWie, but as @Sophia has admitted, she has a habit of making sure to be my regular "daymare"! Not that I'd have it any other way, because along with being annoyingly talented she is also incredibly entertaining. 
I share your feeling about having "sausage" fingers - sometimes I wish mine were more slender, but on the plus side I have a large hand span so it's not all bad.
When I see you playing your fingers seem to move very nimbly around the keyboard, so whatever you're doing, it's working.
"Don't let's ask for the moon, we have the stars." (Final line from Now,Voyager, 1942)
Anything I say you need to take with a grain of salt, because I have no teacher to correct me if I'm doing it wrong. That said, I thought I'd demonstrate for you how I do the slide - it just so happens my current lick has two of them, so it was good practice 
Simba decided to be my assistant today!
Oh, I didn't realise the slide was an actual technique, I've done something similar many times but in my case it was just a mistake! 
Nice close up of Simba - even his paws are beautiful and at one point he poised on the edge of the piano, rather than clambering on the keys - he is so elegant!
"Don't let's ask for the moon, we have the stars." (Final line from Now,Voyager, 1942)
Nightowl Oh, I didn't realise the slide was an actual technique, I've done something similar many times but in my case it was just a mistake!
That the beauty with jazz/boogie/blues.... you can pretend your mistakes were totally planned that way 
If you don't believe it...
Yes, WieWaldi and TC3 have recorded things for me too and it was ever so helpful... so it was the least I could do for you too. Again no idea if I'm doing it right, but at least some sounds came out of the piano
There ya go! We're all rebelling together then 
hebele in his tutorial video, Christian says "Don't tell your classical teacher about this. They don't like it."
I don't remember this, but indeed it sounds like Christian.
Sophia In your second video, I see you are trying to slide diagonal into the big white space; sliding over the end of the key. If I try to do this, it feels very uncomfortable to me. Making the curl even stronger as it is with my way. But it seems it works for you.
@hebele , In the first video of Sophia, she is doing the comfy slide. Leaving the black key where it is the easiest: at the end, diagonal. Same as my first post, before I have seen the B is flattened. This flat B forces your hand to rotate a big, so the middle finger needs either to be curled to the extreme. Or you curl it normally and slide off to the side. It is up to you. Whatever feels better.
Sophia It sounds great. You got the chorus darn good already. A few more licks plus the refrain and you are done. LH absolutely fluid! What should I say, your Ferrari isn't just big in the mirrors, you added honking as well.
WieWaldi A few more licks plus the refrain
I figured with today's session for hebele, I finished my current lick. Then I added the next one (the drone lick), played it a lot of times. Then went back to the beginning of all the licks... and promptly forgot completely how to do it! I think that is why the LH is getting so fluid... I'm getting all my practice in just trying to memorize things
Oops...
Following along here I’m curious: is the F# supposed to be played at the same time as the C and the Bb with the G coming shortly after? Or is the F# supposed to come first with the G playing shortly after at the same time as the C and the Bb?
I tried this and the first thing my fingers did was play the F# with finger 2 as a grace note followed by C-G-Bb with fingers 1-3-5. But that’s not a slide! I was able to do the slide after a couple of tries but found myself wondering about timing. It’s awkward either way!
I love this thread. You blues players are so much fun!
rogerch This is a really good question. I also thought about it in the past. But I never asked someone because my playing sounds okay for me.
The thing that makes me curious - why are you asking, Roger? I mean, if I really dared to ask this question, I would have asked you. Or @TC3 .
@hebele: can you share the video + timestamp where Christian does the slide?
rogerch here is Christian's explanation:
My understanding that it's similar to grace notes. In the comments, somebody asked him the difference he says:
Grace note comes from classical, is very controlled, preferrably played with two fingers and supposed to sound gracious. Slide: preferrably with 1 one finger to create a smeered sound. Control is neglected in order to sound dirty.
hebele I see. This is the reason I didn't find the slide in his video, because I was curious about Christians finger positions. (Not that I would change mine, if his would be different. Nope - I even change his fingering numbers too often.)
But it is slideable. It was instantly in my muscle memory to be recalled. Therefore, I guess he did the royal thirds with that slide somewhat later. Probably around lesson 10 or later. In lesson 2 definitely I didn't play this slide, because I only followed the video.
Maybe you should skip this specific slide for now and go on. If it was the comfy slide without the need for the curled fingers, I would encourage you to do it. Don't worry - you will learn it later, and you are missing nothing for now.
Somewhere in this thread I was complaining about the slide too (yeah yeah cue WieWaldi "you moan a lot" pffttt) and I think I even mentioned it hurt a little. But... I learned it too. And thanks for the video about the slide @hebele - I missed that one too! Interesting!
Edit: Found it! In fact that was the exact same slide (without the C). And WieWie posted a video then too 
Sophia (yeah yeah cue WieWaldi "you moan a lot" pffttt)
No, this is not true. I am not moaning a lot. I am just complaining that my progress is so slow. And I don't like, that I forget more than I learn. And I am jealous that you are learning so much faster than I do. And I am envy, you learn all the advanced stuff in Alfred's like diminished chords while I stick to the Blues stuff only. I mean, Christian only explained the half-diminished chord so far. You play Piano for several years less, but you know already how to diminish something fully. I can only half diminish a chord. And that you can play Chopin, and me not. You know, there is no easy Chopin. Not to mention this Ostinato Jazz. I use Blues as a vehicle to get into Jazz, but you step directly into Jazz playing. And then all this creativity - embedding cats into videos. Doing duets with a hand puppets and all the like. You have two professional musicians as parents giving you all the talent while my parents have trouble to spell music. Actually nobody of my friends play an instrument or is musical at all, and...
...you are right - I moan a lot! 
Edit: 
this is not true!
