On the plastic bag for toiletries...
It is definitely best to adhere to the rules.
They now can calculate how much liquid you have (one of the reasons for the small clear plastic bag) and the maximum is 1 litre. So for example you can have 10x 100ml, or 20x 50ml in your bag. It's one bag, though. So if you have more, split between several bags they won't allow it - whatever doesn't fit goes in the bin, or it's back to check in your hand luggage... and for an airline like Ryan Air that is extremely expensive. I saw exactly that happen to a lady behind me at Stansted. She had about 5 of the correct size bags full to busting... so she then had to choose whether to go back and check in her bag or bin all but one bag of toiletries.
Always best to research beforehand.
In general the rule is:
Each liquid you carry must be in its own container of no more than 100ml (3.4 ounces).
All liquids should be carried in a single, transparent, re-sealable plastic bag of up to 20cm x 20cm (8in x 8in) with a total capacity of up to a litre (approximately one quart).
But always check with whichever airline you are travelling with.
You can always bung stuff in pockets on coats or wear stuff (just don't make yourself ill doing it).
And remember, while Ryan Air have relaxed the strictly one piece of handluggage per passenger rule, other airlines may not have.
Generally it's worth checking as well whether the airline allows you to also have a bag containing any duty free shopping you have done. If not, that again can be an expensive mistake to make.
I would also add that Ryan Air make you pay for your hold baggage - you get 2 options, as far as I have seen: 15kg or 20kg. I went for 15kg and regretted it... far too stressful weighing and packing and weighing and repacking. Some of the package companies - like Jet2 are surprisingly generous in their allowances for free checked in baggage... I think it's something like 22kg.
There is a weight limit on your main cabin luggage - 10kg. Many airlines that don't specify do actually say "you must be able to place your handluggage in the overhead locker by yourself" - in other words - if you can't lift it, you can't bring it! That doesn't apply to laptop bag/handbag... though there are normally (certainly with Ryan Air) restrictions on the dimensions you can have for your handbag. While they didn't seem to be strict on the hand bag on the flights I have been on recently, that could be sheer luck. I just wouldn't risk it.