Bought a brand new house that was thrown up...
In hindsight I should have bought a circular saw for all the flooring.
Tiling is easy, take your time, make sure your bottom baton is level and don't be afraid to rip it down and start again. A circular disc cutter is worth the cash, bit slower but more accurate and you can use it to nibble to get curves for bogs etc.
If I get the chance I'm never laying porcelain tiles again, ceramic "stick" so much easier. Oh and make sure the floor is level when you start and find your 2 lines of symmetry before you start.
hefty corded hammer drill did me for everything.
Doors are a pain to get right (all 17 in a new house were rehung).
Get a good heavy duty saw, a general purpose, a tenon and a hack saw. When they start to cut wonky replace I like Bahl stuff (replaceable blades with v comfy handles.
When drilling really big holes hire a proper drill for a half day and double check you are not going through power/water etc.
Fit an external tap first if you are doing loads with cement etc, stops having to run in and out and open windows etc.
If sanding wooden floors hire a float sander and use a sponge to check for raised nails and use a nail punch to get them down and stuff before using the sander. Seal yourself into the room with tape, open windows and use a decent dusk mask, not a 99p job. Oh, seal the hoover in with you too.
cling film rollers for the next days use.
planning kids? hard floors downstairs and in their rooms, don't have light colours carpets in high travel places (like the stairs/hallway).
different brands of magnolia are very different colours.
buy a load of quality rawlplugs for masonry and plasterboard, use the right ones.
Tell the wife to bugger off if she suggests floating shelves at any point. Same goes for fitting a shower tray that isn't the right size because it looks nice so you have to tile some funky tiling to make up the difference and fill a hole of doom neatly.
mosaic tiles are ace for small areas of trickiness btw.
swop out taps before you tile the pedestal in.