Coming back to samples if you type your postcode into "find an Avon rep near you" they might be able to order some samples of foundation for you if you ask them. I've only just started doing Avon so I haven't seen the ordering system yet but I know they do loads of samples of other things and my friend who used to do Avon said she always used to get foundation samples as they're the hardest thing to buy without testing, so it's worth asking them. You might have one or two reps in your area so if the first one doesn't know what you're on about try another one until you find one who can help.
SCIENCE ALERT Also while one foundation brand might not suit everyone for day-to-day wear, if someone's just going to wear it for a few hours it probably doesn't matter whether it leaves their skin a tiny bit greasy or dry or whatnot as they aren't going to be getting married every day so as long as it looks ok for the day/in photos and doesn't cause any bad reactions, it doesn't matter if it's the exact brand they would buy that perfectly does everything they'd want on a daily basis (e.g. some people choose their foundation based on whether it's easy to remove - is this necessarily a deal breaker when it comes to their wedding day?? It could be if they're super fussy but probably not the most important thing on their mind as a bride compared to looking amazing). I would personally stick with one brand for mixing as they would have similar ingredients - I currently use L'oreal infallible as I find they mix quite well - a lot better than if I try to mix a L'oreal with a Benefit foundation, as the ingredients are not necessarily miscible. It's all to do with what emulsifier they've used to get the oil and water to mix for the base and whether the pigmentation actually presents as the same colour or not in a different base, as different bases can affect how the pigment ingredients appear because what you're seeing is a combination of how the ingredients have reacted with one another and the colour comes from how the particles reflect light and what colour light it reflects, so mixing brands might not always work very well. Speaking of which it could potentially be dangerous to mix different brands for example in an extreme case using some common ingredients in cosmetics, if one has CaCO3 (calcium carbonate) in it and another has any acid (lactic acid, stearic acid, etc), they could react and produce CaOH which is a strong alkali in the tiny amount of water you'd have in a foundation (it has two forms depending if it's liquid or aqueous), which could leave you being sued by someone for permanent disfigurement - sorry to bore you with science, I'm a qualified chemistry teacher in the middle of a career change to MUA. As someone else has said you will need representation of pink and yellow bases - but you may need to mix these together anyway if you have a neutral toned client as people are not necessarily 100% warm or cool toned it's a spectrum just like your skin colour is.
I have also heard good things about the Avon primer but haven't had a chance to try it out yet, I did see one really bad review of it on the Avon website from someone over 50 so maybe it's only good on a certain age range but then how many over 50 brides do you see in an average month? Maybe 1 a year? If that?
Also from experience I bought the Boots 17 Photo Ready Foundations in a range of 4 shades recently (they were on offer, I should have known there would be a reason) and they were absolutely terrible - in natural light they came out green and that's not what you want someone to be seeing in the mirror when you're putting their makeup on!!! Luckily I was just doing a portfolio pic for my BTEC but still ended up using L'Oreal instead - only problem with the L'Oreal is it's rubbish for flash photography. Personally I'm going to take the advice from another thread and invest in HD foundation pallettes instead unless anyone knows any major downsides??
Sorry to ramble but hope some of this is helpful!
Torrie xx