Wanted to make a couple of points about the use of magnets, Velcro and suction cups in your ideas. As a rule, magnet’s run the cost of goods up. And I know your first comment will be how can they be expensive, I see them in all sorts of products. It all comes down to the product, its profit margin and the return on investment. There is no problem using magnets if it is the best fit and not just a quick fix. Also, if you choose to work with magnets do your research to find the right type of magnets that make sense for your application.
Velcro is a very versatile product and great to use in many applications. But you need to think past your use of it and what happens after the purchase. How many times have you put a piece of clothing in the washer or dryer that contains Velcro and seen it stuck to your favorite shirt or skirt? Or it catches all the lint in the dryer and you must clean it out for it to work right again. You have the same issue with Velcro catching outdoor debris on the straps of your shoes. Velcro would be fantastic to hold turkey legs together for cooking but how will it hold up in the hot oven or microwave oven?
Another material that is used a lot in ideas, but not always effective is suction cups. Yes, they are cheap, but they don’t stick to every surface. And they do not hold up well with weight loads that exceed the object they are connected too. Think about how you are attaching the suction cup to the object. If you look at most items that have suction cups they may have a small piece of metal running through the tip that is connected to the object, be inserted into a groove or slot and many other methods.
A suction cup sitting flat on your desk or table has a better holding strength than a suction cup adhered to a mirror in your steamy bathroom as you take a shower. Which is why the device using a suction holding a dry towel in your garage can do a better job than the one in your bathroom holding a wet towel. It comes down to application and environment.
When choosing a material for your idea always try and consider where it will be used the most. Don’t just use a material because it is cheaper; make sure it is effective and proper for the workload you plan on using it. Remember just because it works doesn’t mean it is the best choice of materials. So, when you rush to use magnets, Velcro or suctions cups in your ideas I would challenge you to also include alternatives that could do the same function, so you have a back-up solution in case your first choice is cost prohibitive or impractical.