true, but you can still practice doing lineart by sketching the outline of objects and people, still practice makes anything work
Doing the lineart goes pretty quickly for me. I really enjoy digital inking and I don't stress over it too much so that probably helps with speed. Now coloring on the other hand... takes me FOREVER. I'm not as practiced and I have trouble picking out the right colors.
So it just takes time and practice. Hang in there! 
I've struggled with slow lineart for aaages. I'm still not really fast, but I recently started doing something that bumped up my speed quite a bit. Long, confident strokes with a full opacity brush. Avoid the urge to sketch or "paint" your lines. This probably seems obvious to lots of you, haha.
I've been watching Ursula Gray's videos on youtube151 (illustrator of the Magpie68) and have been kind of studying how swiftly and confidently she creates her lines.
Confidence is really key. I've never trusted my lines. I've always been cautious, careful, meticulous. I've also rarely used a crisp brush at full opacity. I always go for kind of wispy, faded lines (I still like the look of it tbh) and apply them the same way I would approach digital painting. I enjoy digital painting, truly, but this approach was painfully slow and not at all fun for me. Working more confidently is a lot more satisfying.
It just comes with time. Your confidence builds and you'll just go about it quicker.
I don't even have any stabilizers in photoshop since I'm working off a mac, but I've been told I'm pretty fast. But I've been working with my tablet for 10 years now.
It takes forever to draw when you're inexperienced and you redo things one billion times, lack of confidence too.
I use the vector layer in CSP, and it helps me save a lot of time. Although I've always been fast-ish with line art and odn't have very complicated lineart, so I dunno.
I actually sketch out with pencil and scan it and do digital inking. It took me awhile to get to where I am happy now in the process, but like most say...practice, practice and more practice is about the best solution one can give.
THIS! Make sure you are utilizing all the little "tricks" of whatever program you are using. Like with CSP, it is wonderful for buildings since you can just draw one line straight down, several lines across, and then use the vector eraser to erase the extra lines in between. You just have to make sure you are using a vector layer. I use vector layers for backgrounds and word bubbles and raster for most other layers.
Also try gesture drawing to help improve drawing speed. Draw a pose in 5s, 10s, etc to help get used to drawing more quickly.
Try 24 hour comic day too as a challenge! Draw a 24 page comic in 24 hours!
ah, thanks everyone! i thought i had enough experience and confidence but seems like i do need to spend a lot more time drawing. i also wanted to scan traditional work but too bad i don't have a scanner 
again, i thank you all
This is true, specially details that might be 'spike' like among others things. I like the stabilizer, but certain things have to be done with it off for them to come out correctly.
This may not apply, as I use paper, pencil and ink. What I can tell you though is to practice every day. Keep everything so you can look back on it a few years from now and see how much you've improved. Drawing well is usually acquired with a very free motion. I've noticed the more time I spend on having a very free flowing, natural movement to drawings, they're usually much better than anything I've laboured over.
Good luck!
I wouldn't say that, per se 
I'm a digital artist who made that transition from a traditional artist, and a lot of the things and methods I did with the latter really helped my skills in the former.
It's good to consider what s.j.meek has mentioned. Sometimes, the best way to improve and learn a new media is to take in the skills you've gained from another one. For me, traditional art really helped me steady my hand to give neater lines, especially when inking with Inking Pens. As a result, I can easily do quick, neat lines with a flick of my wrist.
i started with traditional too but it's very different when i'm on my tablet. i become slow when i go digital but on the bright side my art style changes dramatically. i don't know maybe i have stupid muscle memory
Yeah, it can be a bit awkward sometimes XD
I think another reason I had an easier time using it was because I had also been doing digital art as a kid with MS-Paint and a mouse. It also helped that I was often staring at the screen while I worked. So when I got the tablet, it felt like that -- didn't need to look between the two. But I do know that some people need to look between them to know what they're doing.
Do you have any artwork we can see? I tried visiting the tapas link in your profile, but it doesn't seem to work.
Also, on the subject of time - don't worry about it. Some people are faster than others with artwork. Go at your own pace. Speed may come naturally to you down the line. If it doesn't, who cares? As long as you're having fun nothing else matters.