Consider your session
I think it's important to ask yourself what kind of ride you are planning to do. If you want to add some intensity or intervals, then is the turbo or gym bike a better option? It allows you to focus all your energy on the set rather than looking out for traffic or hazards.
Ride with friends
I do a lot of riding alone due to the limited time I have to train but if you have the option of riding with someone, this can help to make you feel safer plus two cyclists will be more visible than one. Also, if anything happens there is someone to help. If you're alone consider riding a little away from the curb as it encourages traffic to slow down and overtake wider. It also helps you avoid glass and debris which can collect by the gutter as well as gives you more room to go around potholes.
Think about the time of day
This has probably made the biggest difference to me feeling safer. Think about when the roads are the quietest in your area. I find this is early morning at the weekends or later evenings on weekdays. Also, about what activity is happening. I made the mistake of riding a route when there was a huge car boot event happening so there was 5 times the normal traffic.
Plan your route
Choose roads that are wide or have dedicated bike lanes. Opt for quieter roads over high-traffic ones, especially on weekends. If you are new to cycling and less confident, then why not go to a track or some cycle paths and practice stopping and starting? Also, think about the time of day and when you will come across less traffic.
Make sure you are as visible as possible to other road users. I love my Zoyra Wind Jacket which not only looks great but has reflective detailing so you can be seen in low light. Also, invest in some good quality front and rear lights and use a rear light on flash mode even in daylight. I’ve started using the Garmin VARIA RTL 515 rear light and sensor, which alert you when traffic is within 140m. And of course, wear a helmet, which you can add a light to. Liv offer helmet options that accommodate a light such as the Liv Rev Comp MIPS.
Stay alert and on the lookout for hazards. Not only traffic but loose gravel, ice, sand, puddles, potholes and other road hazards. Slowing down should help you get through them safely. Remember also when you are tired your reactions are slower so make sure you stay hydrated and fuelled for your ride and take rests if needed.
Your ride essentials are not only a repair kit but your phone, some money and some ID. I always wear an ICE ID Bracelet as it gives me peace of mind.
I hope you have found this useful - Ride safely.