I thought I would just mention a few places where you can take arty crafty classes online.  Some of these classes are free but most of them are not.  These are sites that I have personally used.
Feel free to recommend others :)

First the obvious –

Craftsy.com  PAID CLASSES | FREE CLASSES | SALES | ALL CRAFTS
They have classes in every art and craft you can think of and probably a few that you can’t.  They do have a few free classes, often shorter, and they frequently have sales on their paid classes.  Last year they also introduced a paid membership so you can pay monthly and take as many classes as you want.
PRICE:  varies from very low to very high

Altenew.com PAID CLASSES | EARLY BIRD DISCOUNTS FOR NEW CLASSES | CARD-MAKING, SCRAPBOOKING, PAPERCRAFTING
Altenew is one of my favourite brands.  They started in 2014 and have beautiful products.  They started with stamps and dies, are well known for their layering flowers, and have expanded their range of products to include inks, watercolour paints, watercolour markers, alcohol markers, paper, cardstock, washi tape

Their classes usually consist of a few short videos on a particular theme or technique.  The early classes used other products from other brands but as they added their own products, their newer classes use more and more of them.  The classes are run from their Altenew Academy website and some of the classes count towards becoming qualified as an Altenew Educator!
PRICE:  Usually $8.95 with early bird specials available for new classes

UPDATE 2 May 2019
Altenew have made three of their layering classes free. These focus on their layering stamps, flowers especially.

All About Layering 1

All About Layering 2

All About Layering 3

Scrapbook.com  FREE CLASSES | CARD-MAKING, SCRAPBOOKING, MIXED MEDIA, JOURNALING, PAINTING ETC
Scrapbook.com is a great site, you might have seen their videos on youtube. They do a lot of technique and product videos as well as interviews with all the celebs and they go to all the conventions and do live videos from them.  Their website started as a site for scrapbookers, hence the name, but it has evolved and they do a lot of card-making stuff now too.  There is a shop, and they have great sales, but also there is a free resource section that has quotes and poems and titles etc that you can use in your projects, there is also a gallery and a forum, and they have FREE classes.  Most of them involve use of products that are for sale obviously but they are very informative and you can pick up tips along the way.  Tim Holtz has a class there, so does Dyan Reaveley and a few other familiar names.  Since their classes are free, all you need to do is sign up with a username and password and you have access!
PRICE:  all FREE!

OnlineCardClasses.com PAID CLASSES | CARD-MAKING, MIXED MEDIA
Online Card Classes is run by Jennifer McGuire and Kristina Werner and predominantly offers cardmaking classes focused on using various techniques to produce the finished cards.  They also have the Tim Holtz Creative Chemistry 101, 102, and 103 classes hosted and available there too, and these are not card-making classes, but technique classes, where you learn the ins and outs of various Distress products and the chemistry behind them.  Tim is the tag master of course, so the classes focus on making tags, but you could of course make whatever you want ie a card instead.  Also between 2016-2017, they did a series of Crafty Chat conversations/interviews with various well known papercrafters and brands. They haven’t done a new one since but all the old ones are there to watch, and they really are worth watching.
PRICE: $12-39 with discounts available from time to time or early birds on new classes