We help our clients with concepting and like Vassago said, this is done for a fee and with a clearly articulated budget. Who is the client? The GC or property management will want it as cheap as possible. The architect and sometimes the owner's rep or design team will want something they cannot afford (money is no object because it's not their money, lol).
I have found it helpful to present some images found online based on the project's aesthetics. Ask them to provide you with images or examples of
signs they like and equally important to figure out what they do not like. Some people feel very strongly about materials and colors.
Typically, you want to get their brand book, design look book / idea book, their website, or anything with their branding (it is called a myriad of names, so just describe that you are looking for design guidance or inspiration). Then when you have more images of fabrics, wall colors, furniture options, and fixtures you can pull together a few ideas (that you know you can make or that you can outsource).
Depending on how much they want to spend (we offer ranges to them) on the concepts, that will determine how much you show / design for them. Something simple would be 4 options. If they want to be wowed, we'll do a 20 or 30 page presentation, cover page, typography page with font options, and multiple design options. Make sure to request their brand logos (vector) and their fonts. If they don't have those, then that is an additional charge. This is extra work outside the design process. You should also discuss samples. Two reasons - make sure they actually like what is designed and to ensure the fabricator you selected can produce the quality and hit the design goals (and timeline).
Before you spend hours researching something you think they want, it is best to narrow the focus and figure out the design goal. Your time is valuable. If they don't want to pay for this design process. I would spend about 30 minutes picking a few images from online or prior projects and asking them for their feedback.
You want to be careful not to offer something you cannot produce. We had a salesperson that sold a solid giant crystal for an exterior
sign. They thought we could create a 3' x 4' resin cast perfectly clear crystal and just slap it onto the site's existing
sign. It took a lot of creativity and no lack of frustration to create a faceted crystal statue with thousands of individual lasered, silver leafed, and hand painted acrylic pieces. It turned out really nice, but this is not a scenario I wish to repeat.
Good luck!