An idea is a thought or conception, a product of mental activity. A notion is an idea in the most general sense, but the term usually suggests thoughts of more fleeting, vague, or imperfect kind. Whereas an idea can be something fairly worked out or elaborate, perhaps even a plan of action (The student has an idea for how to become an engineer), a notion is more like a whim or impulse—a flurry of thought that hasn't been seriously worked out. Perhaps this half-baked quality explains why notions are so often rejected, challenged, or dismissed! When used in the plural, notions can take on a whole new meaning: small items used in sewing, such as buttons, hooks, and ribbon. 

Items or ideas that are similar have a likeness or resemblance, especially in a general way. The adjective akin suggests a closer affinity or shared nature. The primary meaning of akin is "related by blood," with the root word kin meaning "family relatives collectively" or "a relative." Akin doesn't always imply familial connection, but it does suggest a sameness of character or properties, as what might result from shared ancestry. Akin often shows up sentences that compare one experience, sensation, or feeling to another stronger or more intense feeling, as in "What he felt was akin to love."

Without a doubt, nice is a well-liked adjective. So much so, that it's used almost to the point of cliché! When you are looking for something with a little more heart, try cordial. Cordial means courteous and gracious. It comes from the Latin noun cor meaning "heart." Cordial is commonly used to describe social interactions, as greetings and meetings. While it has cooled off a bit since its earliest uses in English, which emphasized a deeply heartfelt sincerity, it still conveys warmth and friendliness. When used to describe relations of a professional nature, it skews more toward the head than the heart, connoting politeness and civility.