Landscaping and laundry are two easy examples.Separating garage and other storage or parking space from the main rental contract, so it’s an additional monthly fee, can also boost your income from renters.Another opportunity is property investments that add value to the holding, and thus increase the rental income tenants are prepared to offer.

Devices will never replace the impact of in-person engagement.

State law dictates how long they have to keep files but I suppose there's nothing illegal about charging for the storage costs. 

I'm interested in Multi-family apartment homes investing with a small interest in storage and mobile homes.

We invested a lot of money to rehab the property, totally re-landscaped it, painted the garage and storage sheds and added new garage doors. 

It could be emptied a little (piano makes the living room look small, boots imply lack of storage space) but I don't think that's the main issue.You advertise as "No pets" very clearly.

Almost all the bathrooms had no medicine cabinet, small sinks, and no storage under the sinks.

All contracts, options, or other devices not based upon a substantial consideration, or that are otherwise employed to permit an unlicensed person to sell, lease, or let real estate, the beneficial title to which has not, in good faith, passed to such party for a substantial consideration, are hereby declared void and ineffective in all cases, suits, or proceedings had or taken under this chapter; however, this section shall not apply to irrevocable gifts, to unconditional contracts to purchase, or to options based upon a substantial consideration actually paid and not subject to any agreements to return or right of return reserved.

Would anyone be able to help in evaluation/due diligence specifically for Self Storage, Mobile home, and Industrial offerings? 

@Noelle Pritchard Barkley have you looked into self storage as a possible business yet?