It is a myth that all curries should have onions. About 40-50% of Indians, at a rough guess, make curries (not called curries of course) without onions. In my grandmothers kitchen, if you even sliced an onion with her knife, she could tell and would wash her knife with hot ashes to get rid of the smell! For poor people, onions, ginger etc. are quite pricy ingredients off season. My late mother made most of of her vegetable curries (I grew u in a vegetarian household) without onions. Garlic was a strict no, no, it still is, in most of my sibling’s house. My older sister’s husband cannot eat even a tiny amount of onions, he hates them. So my sister cooks everything without onions. They are vegetarians. So you are in good company, as far as Indians are concerned.
I am giving you a few links of some of my recipes below, to give you a rough idea. What you are doing with your curries is fine. To give them an extra umph, you could add any of the ingredients below to the curry paste once it is nearly ready to add main ingredients, with the exception of yoghurt and cream, which is usually added at the end. Talking about yoghurt, use it at room temperature. Chilled yoghurt added to a hot sauce sometimes splits. Also, it is better to use full cream yoghurt or sour cream. Skimmed is more likely to split during cooking.
Phaal and Tindaloo are not my cup of tea. Too many spices, especially chillies, ruin a curry, in my humble opinion. They were invented for lager louts, who were too drunk to appreciate true spices ;)!
www.mamtaskitchen.com/recipe_display.php?id=13922 leave out garlic, if you are allergic to that too.
Curry sauce thickeners;
Besan/Bengal gram flour or plain flour, added to the spices and fried with them.
Thick, full cream yoghurt.
Cream, but full cream, not skimmed
Lightly roasted and ground sesame seeds
Lightly roasted and ground poppy seeds
Ground cashew nuts or skinless almonds
Hope this is of some help. Please feel free to ask specific questions about a dish, I will try my best to help.