The phrase 'conceiving of' is often used to express the act of forming an idea or a concept in one's mind. However, it is always good to have synonyms to enrich your vocabulary and avoid overusing the same phrase. Some of the synonyms for 'conceiving of' include 'imagining', 'creating', 'devising', 'thinking up', 'formulating', 'inventing', and 'originating'. These words can help you express the same meaning in a more varied and impactful way. Using different words helps you avoid repetition and make your writing or speech more interesting and enjoyable.