My little one is 8 months and my tips would be:
Asda sell bibs with sleeves which seem to be a bit smaller than anywhere else I’ve found. They are in the baby section, in small packs. I can try and find a link if it helps.
We bought a vinyl table cloth 1 meter by 1 meter and put it down under the high chair so food thrown on the floor can be picked back up and the mat can be shaken clean outside.
Have a simple high chair like the Ikea Antilop which is easy to clean.
When chopping fruit and veg like a cucumber, I chop the whole thing and store in pots in the fridge ready for next time.
Eggs are quick to prepare and cook. Scrambled eggs, cheese omelettes, or even healthy pancakes (egg, banana and cinnamon) aren’t that messy.
It’s ok to cheat a little, I found in Asda they have chicken skewers (in the picnic section) which is mainly green on the nutritional info so I grab them occasionally for when we are in a rush. Or even a quiche (although watch the salt levels) which can be given cold. Also my little un loves melon so I buy packs of pre cut melon chunks.
For when we are out and about I usually make a cheese and pickle sandwich cut into fingers but I don’t let her feed herself, I break it into small pieces and pop them in her mouth to stay relatively clean.
Whilst variety is great find some staple meals which you can prepare easily. We have a pack of Warburtons cinnamon and raisin bagel thins in the freezer and pop half of one in the toaster for a quick breakfast. The thins are easier for them to eat than a normal bagel and are already cut up for you.