Follow up question - is ryanair substantially different from other low cost carriers within Europe? Would your tips differ for easy jet, wizzair, etc?
No, not really. I don't see the fuss about RyanAir because I usually fly discount European airlines within Europe. While the fine print may vary, most only offer a 8 kg hand luggage, you must pay for food and drink, choosing your seat costs extra, etc. I do like cheap flights and the costs of checking a bag with these airlines tends to often nearly double the price, so I use a wheel-less "backpack" (ebags Motherlode Jr) to avoid the extra weight that hard sides, wheels, etc tend to add. I've done many 7-10 day trips with this bag alone (doing laundry once during the trip) without issue.
I actually prefer RyanAir these days to Easy Jet which at least last time I used them, didn't allow for a separate purse type bag outside of hang luggage (this may have changed - they stopped flying out of Stuttgart years ago), and to Eurowings, formerly Germanwings, which has recently changed their pricing structure in such a way that their flights are more expensive than non-budget carriers once you add in the basics. Shame, that.
My only issue with RyanAir is that that they generally don't fly out of airports that are convenient to me these days - the cost and hassle of getting to and from Baden-Baden or Frankfurt Hahn means the savings go out the window.
I only had one bad experience with RyanAir back in 2012 at Baden-Baden when I somehow left behind just one boarding pass (not an issue anymore as you can use your phone) and they got me for being .4 KG overweight (we just shuffled stuff between bags). I haven't had a bag get weighed on any flight in literally years unless I was checking luggage and I take discount European carriers minimum 4 times a year. But I still make sure my bag is within regulations and don't worry about it.
Given all the factors these days, I'd be more inclined to pick RyanAir over EuroWings - which is Lufthansa's budget carrier. RyanAir still maintains a bad reputation in England, apparently, but I don't think it's worse than other budget carriers and better than some.