@Tamika that sounds like a great idea! What kind of reins did you use?
@Catarina I bought these ones as I didn't see the point in buying expensive ones as we know everything is a phase and having twins we spend enough already. AOMIG Baby Reins, Baby Walking Reins and Toddler Safety Harness, Baby Reins Safety Leash for Toddlers Boys and Girls (Red) https://amzn.eu/d/0epMaIbf
I started when my twins were about that age, maybe a little younger. I started with reins but occasionally walking to nursery with both. The walk us about 4 mins with the boys walking about 15 mins. I then started venturing to the corner shop with both and also practised with them with the buggy. Each hold onto one side. If they let go, they get strapped back in. Works fine. I often take them out for short walks without the buggy but mostly I use buggy and let them walk alongside me. P.s my twins are 27 months