We did a Canaries + Madeira cruise last March. It was our first without children, and we got a suite with balcony.
TBH, the itinerary was not great, as there wasn't a lot of diversity between ports. A lot of seasoned cruisers didn't even get off.
Tenerife - the cruise port is the capital, Santa Cruz, which is quite industrial, and the cruise terminal is quite a big walk from the town. If you are flying into Tenerife, you have an hour's coach transfer and then your check in (up to an hour). When we did this last year, our flight was a bit late, and Tenerife airport was crazy (Covid and Brexit), so we didn't bother with the town.
Fuertaventura - they drop you off at the capital, Puerto del Rosario, which had absolutely nothing to offer last March. We managed a couple of sangrias, before returning to the boat for lunch. Apparently, there are lots of brilliant excursions in Fuertaventura.
Lanzarote - the cruise terminal is near Arrecife. There was a long queue for the coach transfer, so we jumped in a taxi, and the driver convinced us to go to Puerta del Carmen, which was a good move. It had a mile long strip of shops and restaurants on one side of the street, and a beautiful beach on the other.
Grand Canaria - the cruise terminal is in Las Palmas, which I think is the capital. It's a modern city with lots of businesses. It's a 20 minute walk to the main beach area. We had a lovely paella lunch there. There is a modern shopping mall in the cruise terminal area.
La Gomera - you are dropped off near the capital, San Sebastian, and it's a 10 minute walk into town. There really isn't a lot there, so this is one stop where you can save your money and have lunch on board. There are excursions for those who like the outdoors, eg cycling up mountains.
Madeira - noticeably different from the Spanish islands. Don't get the ship's excursion for the cable car - just pay your own way, and remember to get a return. The fish market is amazing with never seen in the UK fish/eels. We had a traditional lunch in an alleyway nearby.