The mage tower will give 5 speed up per 12 hours and is definitely worth the time.
Save your crystals do not waste them for anything. You will need to save 30 by around level 40.
To keep your goods/gold ratio good always use decorations around your buildings that consume goods. When you are first starting leave enough room around them for 2 rows of flowers. The blue flowers give a 5% increase and are the best bang for the buck. If low on funs you can user the cheapest 4% flowers tho. Once you have your gold built up and can open more land you will want to just use one row of flowers directly around the building and then a row of luxurious fountains around that. To save on money you can build your second and third building in front of and beside of the building that you first make so you then only need to decorate around 3 sides of those 2. You will want at least 3 buildings set up this way. The buildings with a row of blue flowers and luxurious fountains surrounding them will have around a 275% increase to the money they give! Meaning instead of the music shop for example giving a little over 700 gold it will give you 2600+ nearly 20 to 1 gold to goods used. This is a very good investment as you can reuse the decorations as you get better buildings (fireworks shop is good you want whatever pays the most gold)
My second tip is save your magic stones until higher level. They don't time out when you exit the game so if say you have 0/50 energy you can use a magic stone and exit the game and in 51 minutes you will be at 50/50 energy you can open the game burn through the energy quickly then exit again and use 1 magic stone for quite a while even though it only last 10 minutes.
Using tip 1 to make some good gold and now your higher level and have plenty of crops and are turning them into gold at a good rate. Save up 1500000 gold... I now it seems tough but it will pay off for you especially if you arent going to buy any crystals... Now if you haven't already unlocked the pyramid spend the 30 crystals you saved to unlock it. Then build it and surround it with the decorations you have. This will be the only building you need for turning crops into cash. Just use the decorations you have to start with once you have enough gold surround it with the 8% small decoration on the inside(joy hieroglyph thing) and winners throphies around that.. With the proper decorations it can make you nearly 200000 per 3500 goods for 1 energy almost 60 to 1 gold to goods ratio.
You can skip the above if you spend money for enough crystals for the eiffel tower it is superior to the pyramid but it either will take forever to save 225 crystals or you have to buy them.