Miniatura is held at the NEC in Birmingham - easy to get to by road, rail and even air! Accommodation on the site if you want to stay there and enough to keep you going for two days. Make it a short break holiday and there is a lot of interesting things to do round and about Brum.
What I can share here is how I go about getting organised for a big show/shopping trip.
I have one of those 'bragging books' - the plastic folder things that 'grannies' keep their ( 6 x 4) photos in....
I take a picture of every room in the house showing where it is up to. I print them, cut them out and put in the folder. Opposite each picture is a list of the things I want/need for that room.
There is also usually a sort of overview list of stuff like more trims, floors etc so that gets listed and filed at the back.
I will also slip in samples of wallpaper or paint chips or fabric - stuff I want to match in some way. It is also useful to have sizes of rooms or spaces you want to furnish; for example this time I need two small matching display cabinets either side of a fireplace so it is good to know the ideal size for these and the actual space I have there. Floor areas for rugs, window sizes, whatever you think might be handy. I may not be shopping for half of those things right now but how frustrating to see something I might want further down the line but not know if it will work.
This is also the chance (hence doing it early) to order some things from vendors for me to pick up. It saves me and them time on the day.