Starting point for operational amplifier design

Hi, i've been kind of stumped lately on how to go about selecting the initial parameters for the MOS transistors on an operational amplifier. After discussing with my teacher i was told that the BSIM3v3 model parameters that are available to us are unsuitable for use in pen and paper calculations with the level 1 model. Currently the method i'm using to design is to choose arbitrary values for Width and Lenght of the transistors and try to optimize them trough sweeping with the simulator. I believe the correct way to work would be to have a solid starting point without needing to make such choices, as i feel they limit our ability to explain the circuit to another student or teacher. Can anyone help? It'd be greatly appreciated since i'm still a newbie at electronics.

EDIT: fixed a typo.

Operational Amplifiers are made readily available by various manufacturers for a numerous applications.

But still its nice to have our own customised design.

I can help you with a set of IEEE papers which i have in my collection. I am uploading them for you. Making a good study on those try designing. All the best.

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Thanks a bunch! Gonna start the read right now.

useful reference:"Op-amp Circuits"