That largely depends on how well you understand the program you plan on drawing with. The technique, fundamentals, and general rules of drawing and painting can be tweaked then applied to any medium — digital isn’t an exception — the biggest shift is simply in learning how to use the toolset and do so efficiently.
When I mostly painted in oils, I knew the confines and necessities of the toolset — I knew going into a painting that I needed my paints nearby and I would group them together with similar colored tubes in their own bags. I would mix key color scales ahead of time on a glass palette so that I wouldn’t need to constantly be making new ones mid-painting. I would buy generally either a linen canvas and head to the wood shop to build stretchers to put it on or just use a wooden panel as my surface. I’d need it on easel which would need to be angled to the right so that my painting arm wasn’t obscuring the model, photo, or still-life I was looking at. I’d need turpenoid/turpentine, linseed oil, and walnut oil for mixing and changing the consistency of the paint, have my brushes arranged with different bristle types and sizes for different paints as well as certain brushes for lighter colors and certain for darker. I learned how much pressure to apply to get a smooth or scumbled/dry look, how to glaze color, how to hold a brush for the most control without smudging wet paint, how long to wait in between layers, how to use both dry and wet layers for different purposes and textures, and a million other tiny factors that make up everything that is “oil painting”.
When I started to move to Photoshop, some of those things were simplified and synthesized like color mixing, paint drying, and brush cleaning, some were just slightly tweaked like the transition of thinners and thickeners to opacity and blending modes, and others were completely unfamiliar like an infinite range of sliders and depth maps replacing my familiar sable and bristle brushes (though over time you can learn how to use brush settings to bring that organic and at times unpredictable nature of real brushes back into a synthetic environment) — but what helped me transition most was simply learning the tools and nuances that make digital painting its own thing. Hotkeys, selections, layers, workspaces, and so on are best grasped as soon as possible so that you can simply practice painting — not constantly be forced to learn a new way to do something as you go along. Not learning the confines of your medium puts up obstacles, moments of pause, hesitation, frustration, and reasons to get distracted. I find this especially key of the digital medium for me, because the thing I like most about it over other means of painting is that I can just sit down and start making shit.
I don’t have to prepare ahead of time, making sure I have the necessary supplies, that my brushes are clean, my paints are sorted, my colors are mixed, my canvas is stretched… these are all things that delay getting that first brushstroke down — and though many people like digital for many reasons, I just get excited about making things and this lets me START doing so quicker. Even when I spend over a hundred hours on a digital illustration, being able to jump right into the first second of it gives me momentum and the motivation to start and subsequently finish a good deal of things. Drawing and painting traditionally combined with learning the fundamentals of Photoshop early on (even before I knew it could be used for drawing) made picking up a Wacom pen click incredibly fast. Though in the 6 years I’ve been digitally painting I still learn new things all of the time, especially ways I can manipulate the tools of the software to cater to aspects of oil painting I miss, it’s those fundamental first steps of learning the confines of the toolbox that digital artists of every level still use.
It’s also important to mention that like traditional mediums, digital can be as little as one step of a mixed-media process –- learn the tools that apply to its purpose for you. I know artists who only use it to bring out highlights of an otherwise all-oil piece for print, others who only use it to overlay color, others still who do their linework in pencil and then paint value and color digitally, obviously many who use digital from scratch, and some who even use digital initially, print, and draw/paint on top of their lines. Digital art does not replace or make older mediums obsolete, it’s simply a newer one with strengths and drawbacks like the rest of them. As new-fangled as it may seem to purists, I can assure you that painting with pixels is shockingly similar to doing so with pigment.