Remember tile is permanent so you would be wise to select something which will not go out of style or be difficult to design around. Earth tones will always be good. That said, I cannot imagine selecting floors independent of the walls. Size of tile is somewhat dependent upon the space. 12" works almost everywhere. Smaller tiles with more grout lines make for better foot security - especially if you will be using polished stone. Personally I believe glass tile is trendy though they look nice. Glass is more costly to install. Make a drawing of your space - floors and walls, then visit a quality tile shop. Look at their displays and purchase a few tiles to take home (they're returnable), then speak with one of the deisgners. Generally a free service when purchasing. They will assist with borders or accent inserts to liven the space. You might combine stone with ceramic or go all the same. Once you've selected the tile, move on to paint. My 2 cents. Good luck.

I ordered towel bar, tissue holder, etc from Ira Woods. They were clearance items and cheaper than a lot of choices from the big boxes. I got my faucet from Deal Yard. American Standard Cadet 3 is also well liked/reviewed. It comes in both one and two piece. The pro to one piece is ease of cleaning behind the seat where the tank joins. Cleaning that, well, on a two piece is next to impossible unless you take it apart. The con is if you crack the porcelain, you have to get an entire new toilet instead of replacing the bowl OR tank. There could be other reasons, but these seem to be the ones to pop up the most. I'm considering a skirted, one piece because cleaning the nooks and crannies of toilets is one of the worst jobs! It wasn't like this before I married and had children, lol. Tile and grout is porous. We are having to remodel our master bath soon because water is getting under there. Whatever "water-proofing" they used when the house was built, has failed. I'm almost positive there ISN'T any water-proofing. I'm going with a solid shower pan to avoid this problem in the future and ease of cleaning.

I have a bad kitchen too..a square, but a bit bigger with 3 doors (one to dining room, one to basement, one to hallway). The basement door opens into the kitchen so that kills space too. We are in the process of figuring our design also. Our realities and tips to save space so far are: We cannot have an island or penninsula. No room to move around the kitchen with those. We come to the realization, we cannot have a 36" stove so we are sticking with the 30". We need to have a counter depth refrigerator so it does not stick out into the kitchen. We actually purchased one already and a big improvement although storage room is not as abundant. But we put our old refrigerator in the basement. We cannot remove walls because we want a formal dining room. Another item we wanted was a stand alone exhaust fan above the stove. Because that kills space, we are going with cabinets above the stove and using a hood under the cabinets. Bummer, but it saves space. We already installed Lowes store stock cabinets in the basement (about 10 feet worth upper/lower) and moved much of our not used often items down there, plus it is our pantry for everything non perishable. Yes, we make frequent trips to the basement. Lowes has the best assembly yourself kitchen cabinets that are very reasonable. NO partical board...all plywood with 3/4" plywood sheves to hold heavy cans. Good stuff.

"How to keep the cost down?" Plumbing fixtures: One of the larger avoidable expenses in a remodel is rerouting plumbing. If you can keep your fixtures where they are, that'll save you a bit. With that written, some fixtures are easy to relocate, some more difficult and more expensive. A toilet can be tough to move, as the floor joists come in to play. If a toilet is moved within the same joist bay, that's a bit easier than having to cut through or head off joists. In general, sinks are easiest to move. Showers and tubs in between. Material choices: You can get decent looking tile and surface treatments for reasonable cost. If you want to "bling it up" you can add accents of more expensive materials. Along that same vein, you can sort of "future proof" the look of the room by not choosing fad materials. Along the same line as the "bling" comment, you can design to an everyday look and use trendy accent pieces to punch up the look of the room. It's easy and inexpensive to repaint a room, or to change towel colors a couple of times a year. It's more expensive and messier to retile. Tile. What pattern? What width grout line? Will the pattern fit in the space that's being tiled in a logical manner? If the "basic pattern" will result in slivers of tile at the end of a course, how to adjust the pattern to get rid of those slivers. Grout type. Grout color. Don;t get stuck having to choose a tile pattern or a grout color the day work begins. Easiest is to have a photo of the pattern you want Show it to the installer. "Can you do this?" Yes? No? Why not? Your other question "...how much research and work I should do on my own?" Research may save you money, dovetailing into your "keeping costs down" goal. The more you know going in, the more planning you do, the less likely that you'll end up with an unbuildable design or detail that doesn't show itself until construction is under way, or the expense and timeline delay ramifications of a change order. Definitely make sure the room fits together. Windows are accessible. Doors and drawers can be opened and closed without knocking in to something else. That your fixture placements meet basic building code requirements. Lighting fixtures are properly located for the appropriate task. Mirror reflection versus windows. Waterproofing. Probably the biggest killer on this website is rotting showers and tub surrounds. You want waterproofing in your shower or tub surround. Least expensive is demo the walls to the studs. Staple 6-mil polyethylene sheeting to the walls and drape the bottom edge of the plastic over the tub or shower pan flange. Cement board then goes over the poly, screwed to the studs. Tile goes on the cement board. More expensive is using a topical membrane. There are several "roll on" or "trowel on" liquid membranes out there like RedGard and Hydroban. There are others, those seem to be the two most commonly used on this forum. There are sheet membranes like Kerdi and Nobel. Again, there are other sheet membranes as well. To use a topical membrane, you'll typically demo to the studs, then screw cement board to the studs, then apply the topical membrane over the cement board and then tile on the membrane. Shower pan: Myriad options. You can used a preformed pan. Some are cast iron, some are plastic/synthetic. You can go deck mud with CPE membrane. Deck mud with topical membrane. Biggest sin there is contractors installing a sheet CPE or CPVC membrane flat on the floor. The membrane itself needs to be sloped. Again, if cost is an issue, you can go with a manufactured shower pan, or a bath tub, and use shower or tub surround panels. No tile. Easy. Reasonable expense. Shower valves? You can spend an easy $1k on a shower valve and the pretty trim kit to go with it. Or you can use a Symmons Temptrol valve. Everything you need for about $100. So...educate yourself. Ask questions. "How will they build the shower walls, from the stud-to-tile?" Make sure they can explain their steps and the rationale behind their materials and methods. So, a few ideas. Good luck!