Soulkeep Towers and Spells Combinations
The best thing in soulkeep is that you have a variety of options that you can use and this includes towers and spells and even hero and in towers as example you will have some cards like common one that are with you in the start of the game and also rare cards and epic and some legendary cards.
Common towers which considered a least type of these cards are good and can make you win a level even if you don't use rare or other epic cards with them and the secret lie in how to use them and how to have them in the battle as every position matters in the game.
When you have a card in corner position then you can benefit from attacking two areas at the same time but you have to consider that this card should have high range and also good attacking abilities in term of fire interval so you can use it well in the battle and in this position.
Other thing you can do is to use a combination of spell and tower and this case will give you a massive power to eliminate fiends quickly and this is like when you use Gear Grease and tower that is slow so you could make it more quick and this will help in eliminating fiends quickly and there are also a combination of stew of doom and gloom owl as a simple combination but good with low HP fiends.
Talking also about spells that gives you extra mana in this in turn can make you upgrade towers in speed or in damage and this is like Mana Mania and if you want a higher range you can use higher ground for fiends to be attacked from far distance and this is the power of soulkeep spells and towers.