It is worth constantly reviewing and, if necessary, refreshing your investment strategy. The problem for many people is that finding recent ways to exploit the money in an Individual Savings Account (ISA) takes time and effort.

However, it doesn’t have to be a time-consuming task. And if done effectively, the rewards can be significant.

As the New Year approaches, many UK savers and investors are looking for recent ways to boost their ISAs. Here are two that I think are worth seriously considering right now.

1. Focus on stocks

I am one of many people who have both a Cash ISA and a Stocks and Shares ISA. But the amount of money invested in the latter exceeds what I have in the former.

Cash accounts are a great way to manage risk. However, the better yields on offer mean that prioritizing your ISA towards stocks and shares may be a good idea for those with a higher risk threshold.

Recent interest rate cuts mean the best paying Cash ISA rate for basic access is now below 5%. For comparison, the average long-term return of FTSE100 AND S&P500 are approximately 7% and 11%, respectively.

Cash ISA returns may also fall further as the Bank of England adjusts its monetary policy in response to falling inflation.

Let me show you what a difference this can make to someone’s long-term wealth. A monthly investment of £500 in a 4% yield Cash ISA would turn into a 257,065 pounds after 25 years.

Now let’s split this investment 80/20, putting £100 into a Cash ISA and £400 into a Stocks and Shares ISA. If this person could achieve an average annual return on their stock investment of 9%, this would be where they ended up 499,862 pounds in both ISAs, excluding brokerage fees.

Past performance is no guarantee of future returns. However, I am hopeful that equity markets can continue their impressive long-term growth.

2. Expand your horizons

Major UK and US stocks dominate Stocks and Shares ISA investors’ portfolios. Likes Lloyds, Nvidia, Rolls-RoyceAND Tesla all are heavily equipped.

However, those looking to boost their investment returns can look further afield to emerging markets for other stocks and funds to buy.

The Franklin FTSE India ETF (LSE:FLXI) is one fund I am considering for my own portfolio. This exchange-traded fund (ETF) holds holdings in 244 Indian large- and mid-cap stocks, which helps investors spread risk.

Since the beginning of 2020, the fund has achieved an average annual rate of return of 11.4%. That’s less than the 14% that an S&P 500-focused ETF would approximately provide over that time.

However, I believe returns could be much higher in the future, driven by India’s rapid economic growth, mighty foreign investment and ongoing government reforms.

The IMF believes Asia’s second-largest economy will grow by 6.5% this year alone. This is significantly higher than the 2.2% and 1.5% predicted for the US and UK.

Wide selection of stocks – from HDFC Bank AND Hindustan Unilever Down Tata engines — provides Franklin Templeton investors with many opportunities to take advantage of the economic boom.

While currency volatility can impact future returns, I still believe that emerging market ETFs like this one have the potential to provide investors with huge returns.