@Oladimeji Sonibare, main ways to add value are as follows:
#1 Increase the Rent. Call some apartment complexes around and ask how much they rent the units for. If you could go see the units that will be great so you know what level of rehab you need to achieve these values.
#2 Increase Occupancy: Fill out the vacant units by remodeling or/and doing tons of marketing.
#3 Charge tenants for utilities if you are not already doing so. If there is only a single meter for all the units look into RUBS. Make sure to include pest control and trash collection if applicable
#4 Add amenities that could give you more cash per month (i.e. vending machines, laundry room, storage)
#5 Minimize your expenses. i.e. If you pay for a portion of the electricity bill, make sure you switch to LED lighting, this will cut your light bill by a lot. The same with water, install water efficient toilets, etc.
#6 if your property is less than 20 Units, manage yourself. Use RentRedi or Cozy, these are great for small multifamily and it is really easy.
It is all about getting creative and come up with ideas of increasing income and reducing expense. Please free to IM me if you have any further questions
Best of Luck!