One way to start out is to take turnes making higher lv gems(4-5)wells and towers all all allong the path and your mana pot up then as the boss moves around the map pick up your gems and move them to maximize the damage and when it comes down to the last lap and you don't have any more mana blow yor gems up
Heres what you should do to start. dont make impure gems, only pure, it helps. go as fast as you can, but dont die, you should be able to figure out how many waves you can take as much. with your experience, id say work on manas, but eventually get the gem masteries, and also the thing that makes towers cheaper, but all the skills are very useful except maybe the bomb one and the slow (imo) mana regen one. I don't know how far you are in the game, but for the first big boss, you'll probably have to go back to the previous levels and get the most xp you can, to raise the skills. Combine gems a lot if your getting stuck, the more powerful the better, and get as many into the field as possible.
pne of the best things - create strong point on bends and INSIDE corners, where towers get the most range. Use trenches here, and spam in the waves!
here is what you can do, always make pure never make non pure i always use non pairs for bombs. when your level is hi enough make keep on buying the less cheaper tower. i always combine gems and try to build 9 towers always because that gives you a lot of xp. also throw a lot of 1-3 level gems and kill monsters with gem bombs. this will help a lot i think
Build a lot of water trenches, a lot! if you dont have enough mana useonly on the corners, and put the Red Gems there, this way you can deal Splash Damage in a lot of enemies.
Tr to put you Poison Gems and Purple Gems at the begginning, cause then you can destroy their armor before the other gems attack, and the poison attack with the same intensity with or without any armor.
You shouldnt build a lot of Blue gems in the same place, cause if the monster are already slowed, why should you spent this especial?
Orange gems arent so useful, so if its possible, use them as a bomb.
Cyano gems are good in a big number, this way the chance of stop the enemie is much bigger, you can also combinate Blue and Cyano gems, this will also make it better.
This is all i remember, i dont play Gems Craft weeks ago..
Create the highest level gem you can at the start and let loose 3-4 waves. From here build a few towers and simply be smart about which gems you place down. Don't focus on creating 10+ towers, instead try for around 3-4 level 5-6 gems.
If you manage to build your mana pool to over 11000 you will gain 2 times the amount of mana back from kills, I always use this number as a stopping point. Once I achieve over 11k mana I focus on creating at least 5 level 7 gems. When I see that I can let loose multiple waves at a time and not be stopped, I continually increase my mana pool for extra points.
Hope those tips help for a few of the earlier levels and for scoring a bit higher after the first epic battle.
