When the economy/housing market stalls, licensed trades and stores like Home Depot see an uptick in business from home renovations. Unwilling or unable to sell, some homeowners will try to make the best of the home they have. In theory this is a good idea. At least until people start adding in all their other ideas.

Bad Idea #1: "Make it My Own!"
Your personality should deck the walls and halls but your hard surfaces need to be timeless. Tastes and trends change as fast as interest rates. A few years ago people were nearly shiplapping their refrigerators. Today? The sight of a single horizontal board gets an eye roll. It is far easier to change out paint colors and decor then it is to rip out that snazzy glass mosaic backsplash that was all the rage in 2017 and today instantly dates a house.
I should know. I famously tiled my shower with pennies, added plaster medallions to the walls and installed a floating bed from the ceiling rafters inside my first house. It was super cool. It got my house into a magazine! It also made the property much harder to sell because it was "too quirky."
By keeping your hard surfaces (cabinets, counters, tile and floors) in "boring" neutrals and whites your house can evolve with you. You are free to add in and change out your personal flair through furniture, pilllows, rugs and decor. There's a time and place for terracotta tile, lacquered cabinets and heavily speckled granite. That time and place is likely not going to last very long.

Bad Idea #2: Floor vs. Era
Grey faux-wood vinyl tile did not exist in 1910 bathrooms. Distressed barn wood laminate would have been found absolutely nowhere inside a mid-century home. While we expect to modernize and always opt for superior materials, stay consistent with the era of the home.

Bad Idea #3: Mix Yesterday and Today
We've all seen a dated kitchen with ancient appliances, showcasing a brand new backsplash. You can't miss it. The sparkling surface contrasted against 20-year-old honey oak cabinets screams out to you: "FOR THE LOVE OF TAYLOR SWIFT FINISH THIS ROOM!"
Renovating a single element of an otherwise dated room will only make things worse. Save up and finish the room. That stunning new marble vanity is ashamed to be sitting next to that 2005 yellowed, cracked shower insert.

Bad Idea #4: Ignoring Undertones
There are about 500 different shades of "white" at Sherwin-Williams. "White" can still have pink, grey, yellow and even green undertones. These little nuances are almost impossible to detect in the store. Once applied, they reveal themselves in all their glory against true white trim.
Buy sample paint cans and sample flooring pieces. A few drops of black or yellow in a paint can will still look white to the human eye but may throw the rest of your design choices out of whack.

Bad Idea #5: All the Transitions
When renovating single rooms, make every effort to keep the flooring consistent between spaces or redo all the flooring entirely. There is no unseeing a transition train wreck where cherry hardwoods in the foyer slam into dark grey LVP in the kitchen, which slams into creme carpet in the living room, which slams into rolled vinyl in the den.
There are more transition strips in some houses than well thought out decisions. A menagerie of flooring does not add a unique personality to each room. It adds more work down the road once you realize you now have even more remodeling to do.